That is a very interesting rifle. I believe the fore end pin was captive, and had a flat filed in the middle, so it only required a quarter turn to release the barrel.

It's a shame someone drilled and tapped the receiver for scope mounts.

What's the caliber? It's not a .22 High Power is it?

Do you have a picture of the tang with the action out of the stock? I'd like to see how they did that.