Hi Tom,
Neil C would probably be the best person to answer this....watch can be dated easily by its serial number, to me it appears to be a bog standard geneve, 20 microns gold plate over a brass case (same for crown) probably from around the late 60's very early 70's, the $1 investment is a great one, in the uk they change hand son the bay for about £60 to £100 although the present condition of this one is not great, it could easily be improved upon.
Snoopy