Webley MK III Spring Replacement

Well I have been waiting on delivery of a new spring for my Webley MkIII so was pleased when a package was delivered today. However, that turned to disappointment when the spring was obviously the wrong size. Whilst I didn't expect an 'exact' sized replacement this example was impossible to fit without machining a new guide, packing out the piston, and shortening the spring by several coils. i.e., not a replacement at all. I emailed the seller to let him know but wondered if anyone had a source for the correct spring?

Cheers,
Chris