
Here we have your everyday, run-of-the-mill mystery Model 39. Hardcore 39 types have likely already noted an aberration or two and are well on the way to a bunch of others. That's cool. So cool, in fact, I'd appreciate your noting them below.
In the meantime, onward to a second pic . . .

And like the above left side, the right side also provides a few thoughts, surely.
Here's a little background before yet another pic goes up:
I found this gem of a mystery in a literal hole-in-the-wall gun shop about 60 miles from my usual haunts. The elderly gentleman who owned the shop wasn't able to provide much knowledge about it, other than the standard deviations from the everyday Model 39.

From beneath.
And, for comparison's sake, another Mod. 39 from my collection . . .

I will assuredly appreciate some input!