R.F.I. NoI Mk3* 1972 dated.

[Thunderbox]

I don't think you need to remove the binding for proof - they have done hundreds of these rifles without any such requirement. I don't have any of my wire-wraps to hand to check, but the Proof Houses obviously either use a small stamp on the rear of the barrel, or make some kind of an exception where the barrel is inaccessible.