I've rewritten this post three times to try and explain what I've been told is going on. This isn't an uncommon set=up anymore. We're starting to see used fire-arms coming into the US here, especially from Scandinavia, set-up in this manner. What I'm told is that this is an issue of practicality in these countries. Firearms ownership laws are strict. The rifle is obviously older than the mount. It probably passed from one generation to the next. The rifle is a practical tool. If it's given to you, you try to make it work. The Weaver/Picatinny system is well accepted in Scandinavia. You want a new optic/red=dot to hunt moose with. You can't justify the cost of the claw mounts and it may not even be practical to put a red-dot in claw mounts. So, you slap a Weaver style rail on your Drilling/Combination-gun/Double-barrel shotgun and off you go. The rifle may not have cost you anything up front, and you may not see the romantic side of the equation. To you, it's a meat getter, and it's cheap. Again, I'm kind'a just repeating what I've heard, but it does seem logical enough to me. No comment on how classy we, as collectors, might view the concept. Best, Norman4