Old Gold watches get listed in several places on Ebay.  To make your search simplier the list below picks up auctions for Old Gold Watches, Vintage Gold Watches, and Antique Gold watches.  That brings back a thousand or so auctions, so I need to add some code that subdivides the watches into smaller groups.  Womens, vs mens would be one possible division and I am sure a more detailed examination of the listing titles would suggest more. 

There is quite the range in watch values.  Some of the old watches were the really expensive ones and collectors bid high for them.  I suspect there are also many which the heirs found in grandma's drawers, which no longer run, and which are poorly described.  I am not a watch person, but this looks like an auction category where someone who has learned to identify and repair these old watches could make some serious money.  There must be a lot of sleepers.

As a strategy, I know bidders sometimes troll the new listings that come up with a Buy it Now and hope to grab seriously undervalued items as soon as they appear.  I will be adding this to my Make and Sell website as a possilble hobby/extra income source for a would be horologist.