FYI, if your cylinder's charge holes are counterbored for the cartridge rims, it is most likely the original .357 cylinder rechambered to .44 Spl. It could just possibly be a shortened Model 29 cylinder - see if a .44 Mag will chamber. If not recessed, it is probably a Model 24 cylinder.
As to value, it is clearly a highly prized shooter, but collector value is nil.

Larry