Looks like you have a heavy barrel Model 64. This is the stainless steel version of the Model 10. It should have the model number stamped on the frame behind the yoke. Swing open the cylinder and you should see the stamping.
Most of these did not have the lanyard loop. This was probably a police or security gun. I'd put the value in the $400-$500 range.
Trying to identify my .38 special
Linear Mode
