Here are some very general guidelines on how to rank and compare vintage watches in a physical sense. Obviously, make and model have the most to do with the overall equation in terms of value but these physical characteristics can still give a collector a basic idea of the overall intrinsic value of a given wristwatch when compared against like examples.

1. Case Type: A case with screwed back is generally more desirable than one with a snap/pressure fit back due to increased water resistance. Any given multi-piece case is usually preferable to a front loading “monocoque” one-piece case, a style which was popular in the early 1970s but is now out of fashion. A 3-piece case with back, midcase and separate bezel is generally considered superior to a 2-piece case with integrated/formed non-separate bezel.
2. Case Material: An all-stainless case is almost always superior to one with “Stainless Steel Back/Base Metal Bezel”. The latter is the sign of a more cheaply constructed watch. Gold plated watches are usually plated over base metal, some also having steel backs and some watches have solid gold bezel/midcase and stainless backs. Generally speaking these “two-tone” watches are not as desirable as steel watches but there are exceptions by brand, such as gold capped/gold top Omega Constellations from the 1950s & 60s which are essentially as valuable as their steel counterparts all other things being equal. Likewise, watches with solid gold trim such as bezel, crown, etc are not as sought after as either all steel or all gold. For gold models, solid 18k almost always ranks 14k or lesser carat weight like 10 or 9k. In the case of classic Hamiltons, almost all of their gold models were 14k so an 18k version will definitely fetch a premium. Pink and white gold are more highly prized than yellow and platinum is considered the king of precious metal watches with a premium attached. Sometimes a steel watch will be considered more valuable than a like gold model, such as certain classic Patek Philippe models, due to there being fewer produced in steel than in precious metals. And in other cases, a gold model will be significantly more expensive than its steel counterpart, such as manual wind Valjoux 72 Rolex Daytonas. Again, this is due to scarcity of production leading to desirability, so it pays to research the individual collector’s criteria for the brand you are interested in.
3. Movement: Generally speaking, mechanical movements are greatly more sought after than most quartz or tuning fork style movements. Automatic (self-winding) mechanical movements usually rank manual ones. Automatic movements with full rotor are superior to those with partial-rotor movements aka “bumper”. Movements with more jewels are considered slightly more collectible than movements with fewer jewels all other things being equal (such as a 31-jewel caliber 3019 Zenith El Primero vs. the 17-jewel version). Jewel count is a bit of a gimmick, though, as it was often predicated on export destination and avoiding protectionist tariffs (i.e. fewer jewels = less import duty entering the USA) than any real horological reason. Likewise, some watches feature a multitude of useless jewels to boast of a high jewel count and thus claim some sort of superiority. But in general the number of useful jewels you will find on better quality vintage watches will be between 17 and 31 jewels and the higher number gives a slight bit of caché. Likewise, adjustments do not really mean much to the performance of a watch that was adjusted 30 to 40 years ago, yet it is still the sign of a quality movement and hence will still often result in a premium. Similarly, a movement that is “In House” (movement manufactured by the watch company themselves) can often lead to a price advantage over a similar watch where the movement was sourced from a third party. A perfect example of this is classic Rolex vs Tudor watches: the cases and crowns are manufactured to the exact same specifications and the dials and hands can be similar. But the Rolex movement is proprietary and in house, while the Tudors’ are provided by third party ebauche suppliers such as ETA and FEF. Hence two extremely similar models will potentially have a big price difference in favor of the Rolex due to what is under the hood.
4. Complications: Complications refer to the extra things a watch movement does beside tell time. For example, a date feature is actually a complication. So is a chronograph or second time zone function. Very generally speaking and with a lot of exceptions, complications add value to a watch. In other words, a watch with a date will be a bit more valuable than a very similar make & model without date. Chronographs are often more valuable than other watches produced by the same manufacturers. With big exceptions for early and special chronographs produced by Longines, Vacheron, Patek, etc 3-register chronographs (constant seconds, hour & minute counters) are generally more prized than 2-register (constant seconds & minute counter only) versions, particularly once 3-register chronos came into widespread use from the 1950s on. Chronos with flyback function (instantaneous reset and restart) or rattrappante (two independent seconds counter hands) also fetch a premium. Watches with a combination of date, day, month and/or moonphase displayed on the face tend to be more valuable than simple time-only models. Watches with chronograph and integrated calendar functions are considered extremely desirable. And most desirable of all are perpetual calanders and perpetual calendar chronographs, although this is more of a modern phenomena, with nearly all vintage wristwatch calendars requiring some form of manual adjustment to account for 30-day months, leap years, etc (pocket watches and the occassional ultra rare 1920s Patek Philippe notwithstanding).
5. Sports Models: Currently, we are living in a period of great demand for “Sports” or “Tool” models with rugged build quality, good water resistance and purpose built design. Watches like the Rolex Submariner (designed for diving) & GMT-Master (for pilots and world travelers) and the Omega Speedmaster (flight qualified by NASA) remain immensely popular and sought after despite being produced in large quantities through the years. Often with such model lines, older variations are highly sought after, as there are design peculiarities and vestigial variations that were produced in far fewer numbers than the later “standardized” versions. Mainly I think the appeal lies in the fact that the men of today want to be able to wear their vintage watches on a day-to-day basis and not just special occasions. So these robust Sports models, which are also often larger than the dress watches of the same era, seem to fit the bill for both cool factor and practicality. Therefore, vintage Sports watches will be priced more aggressively than a simple dress watch of the same make and time. A perfect example of this is a common Omega Speedmaster Professional from the early 1970s, which will be priced about 4 times higher than a steel Constellation chronometer dress watch from the same period. Boys like toys and a good quality vintage Sports model is a very cool & masculine toy to wear on one’s wrist and, individual tastes aside, is frequently perceived as more desirable than a simple dress model, despite any of the latter’s elegance and mechanical precision.
6. Dials: In an extremely general sense, for dress watches black or blue dials are considered to add value over the usual silver or off-white due to relative scarcity of production. Double name retailer dials, such as those with Türler or Meister added to the normal dial text, should definitely should add some value. Those genuine dials with Tiffany & Co, Cartier, Serpico y Laino or Joyeria Riviera added command a major premium. Gilt/gloss is usually more highly prized than matte printing (particularly true with vintage Rolex). Guilloché/engine turned dials that exhibit a textured pattern on the surface of the dial (such as honeycomb or lotus) can also add to collectibility over a standard dial in some cases. And strange and unusual dials of otherwise relatively common watches–such as those with inverted printing, extra text, different colored print than normally found, etc–can give a watch extra appeal. These sorts of variations are usually found only early in the model line before all dial text was fully standardized and like an early proof of a coin, can be quite exciting to collect.