The S&W Model 64 is the Stainless Steel version of the "blued finished" Carbon Steel S&W Model 10 .38 special. Both revolvers are "K" frames. There are 5 frame sizes in the S&W revolver line up. The "J" frames are the smallest. The "K" frames are the medium service size. The "L" frame are a beefed up frame version of the "K" with a full barrel length ejector shroud. The "N" frame used to be S&W largest revolver frame. The "N" frame supports .357 Magnum, .41 Magnum, .44/40, .44 Special, .44 Magnum,and .45 Long Colt. The "X" Frame supports .460 S&W Magnum, and .500 S&W Magnum. Hope this helps with your question about S&W revolver frames.
Medium
N frame S&W Model number.
K
Open the cylinder its on the hinge closest to frame
It is a J frame, the smallest. It is standard carbon steel. Also called the "Chief's Special."
J frame, usually in 38 special
Yes
model is stamped on gun frame inside cylinder housing
K frame
Blued J frame vs Stainless Steel L frame J frame holds 5 L frame can hold 6 or more
Model numbers are stamped on the frame under the yoke since @ 1955.
400 or so