Cuckoo Clocks For Sale

If you cannot find anything online–try an antique dealer, an antique auctioneer, maybe even an upscale jewelry place that sells watches or clocks. Use the telephone and call these and maybe get a lead from them.
Good luck

go to an antique dealer and get it appraised. this may cost you a bit of money but if it valuable it may be worth it for insurance purposes. best to go to one that specializes in timepieces.

I’ve checked on Ebay before to see what things are selling for. Don’t just check the active listings, go to the Advanced Search, type in your basic desription like "Hamilton Sangamo Clock" and mark the box that says "Completed listings only". That way you can see if anyone sold one before and what they got for it. Good luck!