Indeed it would be a nice gift for your pops...
Shouldn't cost too much... we have a forum member here ID (chronodeco) who could help you out... he pretty much is one of the main guys that takes care of our vintage pieces... (at least all of mine)
prices are reasonable through him... with a full overhaul probably looking at 300-400 bucks... maybe a bit less... maybe a bit more... if all the pieces are there, should be an issue of just disassembly and a new mainspring with a lube job...
Lots of inquiries for Top Times...
nice I like it~!
