Guy, I have 3 webley pistol springs that are surplus. They are from pistols that I changed the springs on as power got lower than I liked, so probably wouldn't need any shortening. ! is a Junior spring, the other two are from either Premier or Hurricane.
If you happen to have a good piston seal for a Webley Falcon, I'd gladly do you a swap. I may also be interested in a complete piston and seal for a Relum Tornado.
The South of England has 2 good things, the M1 and the A1. Both will take you to Yorkshire.