Dorian, as far as the offering for 54 quids concerned, I also got this offer(which meant giving up the serial! for new parts).
lol then you have to weigh up what you want most, a damaged frame with an X-serial or a new frame without something only you know is actually there. Thankfully it was only the nose bridge that needed work on mine so I was happy I could keep the frames.
Heres an idea, look for a bog standard pair of X-Metal juliets on eBay, attach the left arm to your current frames, keep the original arm then send it in to be replaced, then you have an extra pair of juliets as well, everyone wins lol
You can NEVER have enough Juliets, ask Terror :-)