Flight/Sgt Perkins is who you should be looking for not Jenkins.
Aircrews are only issued with the Air Corps roundel and now the new Unit Flashes.
All other patches; wings,Sqn patches, aircraft types and cadet classes, are paid for by the individual's themselves and are a limited run. So I doubt very much that anybody would have a 'spare' set.
People obtain patches at airshows by trading with crews and these are usually fellow aircrew.
F/Sgt perkins may have a stall at the Bray Airshow as he has done before.