Hello
I believe the model you indicated in your Post is wrong as to the frame size. S&W produced a Model 31 & a model 30 but it was in a smaller frame than the K-frame, Which is a medium frame revolver and the Model 31 is a smaller -J-frame, with fixed sights. This revolver was chambered in .32 S&W Long caliber, and they were more common, than a K-32 and most came in a 4" barrel. The K-32 was a K-frame medium sized revolver, and they are a Masterpiece series Target revolver that fired the .32 S&W Long caliber as well, and came with adjustable sights. This model was rare and little over 3,000 of them made. Average price on a decent-J-frame Model 31 or 30 is $250.00 and prices for a K-32 revolver range from 1500.00-3000.00 if one can locate one. I hope this helps, hammerdown