Yes
N frame 357 Magnum
Yes, a model 66 is a K frame revolver.
An N frame .357 Magnum revolver.
No serial number = no answer.
Two places. On the very bottom of the butt itself, or stamped on the frame where you must open the cylendar release first.
Frame and bottom of grip
No
K frame.
It is a K frame. The original .357 Magnum was an N frame (Model 27). The K frame is smaller and lighter.
100-500 USD
L frame, .357 magnum, full length lug, 6 shot