Not marked AFAIK
Gun shop, gun show, old catalogs
25-200 usd
Look on frame inside the cylinder area to find the model number of a Smith and Wesson 357 mag snub 2 in stainless barrel
$250-$300, depending on exact version and condition.
Model 15
L
It should be a model 15-2 and manufactured in 1979.
S&W, e-gunparts.com, Brownell's
Winchester, Marlin, Rossi (and maybe a few others) make lever action rifles in .357 Mag... I personally wouldn't pick that cartridge for anything other than a pistol, or if I were shooting in a cowboy match (where the .357 isn't allowed for the most part, anyway...) But if you need a long gun in .357 Mag, there are plenty out there. Good luck.
100-500 or so
100-450 USD
Yes.