It's hard to say exactly what you have, but 44 Winchester is another name for the 44-40 cartridge and a lot of Smith and Wesson's revolvers from the 1800s were copied by Belgian manufacturers with varying degrees of quality. Value is unlikely to exceed a few hundred dollars.
No more than 50 USD. For that, it would need to be NIB with all paperwork and a perfect box.
Samuel Colt invented the first revolver. I'm not sure if it was a six shot but he invented the first revolver.
Need a detailed description of all markings and features and the serial number.
Impossible to answer without knowing who made it.
It is a Smith & Wesson, possibly a model 17 K-22 Masterpiece. They were made from 1947-1993 (in the blued version shown in your photo) and are extremely good target guns.