The barrel on your ProSport is German, and the stock is probably Italian. So you are going to have to sell it back to me, yes?
I think it's time you invested in a decent pre-War BSA. Get one that is not collector's grade, put in a nylon parachute, proper guides and spring and put a scope ramp on it. Then get a TX200 CD trigger unit and have that grafted on to it - T20 has one of these and it is pretty good. You can make up a full-length laminate stock made up for it. It will be as British as pork pies and I think you will like it. The build quality on some of those old BSA is truly remarkable.