Best bet is to ask the proof house for a recomendation, if you don't have a pet gun dealear. The offence with any banned item coming under the firearms act, is pocession. don't have to prove you own it, you have it eg your guilty. Holding something on a non UK ticket or permit is a minefeild area. Best get it into store at a local gun shop, no more than a couple of quid a week. In defence of British firearms officers, they can be sensible. When I was getting divorced I knew sh'd stir it, so I put my guns in store with a dealear. Sure enough she went crying tio her local bobbies, they phoned my FA officer who phoned me, and I could tell him exactaly what I'd done and why and how. He was more than happy. No further grief.