Thanks, 4seventy and aromkr. Your comments about the operation and significance of the "pin" are very much appreciated. I literally had no idea of its existence (and less so about how it functioned). If there was a good case to be made for including an owner's manual with a new rifle, this would be it.

As far as the screw damage, I'd agree that it isn't significant and is certainly repairable. The thing is, of course, that the screw should not have been damaged in the first place.

As for the type of loctite that was used, I will have to send an enquiry to the dealer. There will be plenty of opportunities to test-fire the rifle over the next two years (before our next DG hunt...