I just became a member of this fraternity with my recent purchase of this M57. I really don't understand the current fascination with short barreled, large caliber handguns. The magnum calibers really need to have a long barrel to realize their true potential.
I have a 4" 29, and while I don't find it all that objectionable to shoot, the longer barreled guns are easier to get that last bit of performance and accuracy out of.
Anyway, here is my NIB M57, serial # points to a manufacture date in 1978.