Parts that are available are easy to replace because they are interchangeable. Elgin watch parts are widely available and easy to find, and these watches are not difficult to repair. Parts for European watches, however, are becoming more difficult to find. I therefore collect Elgin watches. However, Elgin watches were produced by the millions and their abundance makes them less desired by many collectors.
Early wristwatches are usually difficult to get parts for and difficult to repair.
After 1950, however, technology had improved considerably, and watches made since then are much more reliable and easier to repair. I prefer Swiss wristwatches made between 1965 and 1980. Most are not old enough to be collectible and can be found at very low prices. The use of white alloy hairsprings in modern watches dramatically improved their timekeeping. The use of shock absorbing jewels, such as the Incabloc System, dramatically improved their reliability.