In my small collection of Model 39s, I have noted several minor changes that I don't think have yet been documented. They are described below with the brackets in years of when they took place. My collection is extremely small and the brackets are large. I would appreciate any assistance in narrowing these brackets.

1. Between 1976/7 and 1977/8, the contour of the top of the slide lock notch on the left side of the slide changed. Previously it had been in the form of an inclined "S"; afer the change it was a straight line. The change was probably made to simplify cutting the notch.

2. Soemtime between 1970/1 and 1976/7, the magazine release button gained a screwdriver slot on the face, probably to facilitate unscrewing the button from the catch.

3. Sometime between 1979/80 and 1981. the locking lug on the barrel was left at its full diameter all around the circumference of the barrel such as is found in the Tokarev pistols. This is also the configuration used in the second generation pistols; 439, 539 and 639. Peviously, the locking lug had been cut flush with the barrel body at the bottom. The new design eliminated a machining operation, saving money.

4. Sometime between 1970/1 and 1977-8, the forward facing leat spring of the rear sight was narrowed. Prviously it had been .350" in width; it was reduced to .310".

Any help in determining what year these changes took place would be greatly appreciated. Also appreciated would be information on any other minutia that I have overlooked.