Could also be a 14381, I think? If you have it opened, you'll find the reference on the inside of the case back. Movement will be a caliber 551, a nice watch indeed.
The bracelet looks like a 1040 with 518 end links, made for later C-shape Constellations. Note that the end links must have been filed down to fit the 18mm lug width on your example, as they're 19mm originally.
The value of the bracelet with the filed end links will be roughly 100€ or so. The watch itself - note it's gold-capped, not solid gold, which means there is a layer of gold over a steel case - will, in this condition, be very, very roughly 1000-1300€ I'd say. If the dial is in fact in nice shape and the discoloration we see in the pictures is merely a result of scratches on the plexi, it might be a bit more than that.
As
@gatorcpa said, the crown is a replacement. Not unusual for this to happen during a service. It sounds like it hasnt been serviced in quite a while, though, which means it's advisable to not use it much until you either sell it or bring it to a watchmaker.
If you indeed want to sell, despite it being your dads watch, don't have it serviced beforehand. Just take good, clear pictures in daylight and put it on eBay.
