Mount loks OK; certainly it is not one of the repros which are on the market these days. The scope pouch is the no8mk2, which came out in 44/45.

The serial number on your scope bracket matches the number on your forestock (and I would assume the number on your receiver). Does the scope number show on the buttstock? There should also be a large S51 on the bottom of the butt behind the wrist.

Scope case does not appear to match the rifle or the scope.