For those that have extensive experience with this, you may want to skip this, but for anyone who is new to watch collecting or has only recently wondered IF they should restore Grand Dad's pocket watch, read on....
First, Grand Dad's or GrandMa's old pocket watch.
If it is not being wound and used on a regular basis, you need do nothing, it is only if you intend to run it regularly that you might want to think about a service or restoration. Sometimes just a wee display dome is all that is necessary for the family to see and appreciate the old workhorse that served for so many years.
A lot of old pocket watches may have less than 15 jewels, 7 being the most common low jewel count. In this case, extensive wear is usually found in the pivot holes of the plates, owing to the metal-on-metal wear associated with having no jewels as bearing surfaces. These types are the 'Model T' of watches, and originally cost less than their full jewelled counterparts. Wear at the pivot holes may require bushing of the plates, which leads to extra expense, and usually it is not worth it, but it depends on the maker, of course.
Which brings me to the main point.
If you are thinking of trawling eBay for vintage watches with the intention of having them repaired or restored, keep in mind it is a lot like vintage automobiles. The better the starting example the better the result will be. If you start off with something in reasonably good condition, chances are the end result will be that much better. Start with something very worn and damaged, and not only will there be much higher costs to repair it, but the end result may be cosmetically poor, regardless of any refinishing.
So that cheaper version of the watch you're after may be cheaper for a good reason- it may be badly worn or worse- something someone has given up on, for very good reason.
That said, you don't want the most expensive example either, the top prices on eBay are ridiculous, as anyone will tell you.
Examine any and all pictures associated with the watch, they will tell you how it was treated. Dings, scuffs and scratches on the case are one thing, but if you see a lot of tool marks and damage on the movement, it might be wise to move on. We see a lot of butchered up movements, and sometimes the damage is beyond economical repair.
It is also worth noting that the more expensive brands tend to get treated better, with good service records in keeping with the appreciation of their initial cost and preserving their value.
Finally, it is usually better to buy old watches hands-on, at a NAWCC mart, for example. That way you can see clearly what you are buying, and ask questions about the piece with the seller right in front of you. Members of the NAWCC are usually very knowledgeable, and I can recommend becoming a member for anyone interested in collecting clocks or watches.
Happy Hols, everybody, and see you in the New Year!