No4 Mk1/2

[XL39E1]

It's not the first "Fultons" rifle that I have had through my hands that has not been proofed.

Paul, The London Proof House mark appears just above the "ENGLAND". The same is mark probably on the top of the bolt handle too, and generally the barrels were marked at the muzzle end around the Bayonet lug. Back then though shooters would buy barrels just to keep a spare and swap them, so non proofed barrels are quite common!
It looks like a standard 1960's Fulton target conversion. They did hundreds to customer orders.