Barrel has been replaced with an 8x57 barrel from a KAR98a.

That's what happens when you spend all your time looking at the photos and don't read the text carefully enough. Boy, is my face red!

I think the action will probably do fine. I have seen any number of rifles fitted with German claw mount bases dovetailed into the receiver ring, where the dovetail extended all the way through the receiver wall, exposing the bolt lug recess. Although those rifles would probably not stand up against modern proof loads, they have been in use in the hunting field for decades with no ill effects.

I would still use the lanyard, however.