Sorry can't help - but don't throw the caliper away, seemingly the front ones are quite easy to get hold of but the rear ones not so & you could just swap the seals if that is all that is gone.
The rarity of the rear calipers has nothing to do with using rear calipers both front & rear with 180/160 discs of course
Can you point me in the direction of a front caliper, please?
I have stripped, cleaned and re-built the rear caliper with the existing seals. I conducted a 24 pressure test (bungee wrapped tightly around the brake lever) and there was no leaking, I hope there was simply some gunge between the seal and piston. I would like some spares though!
Ah! someone sent me a link to a shop selling them NOS complete with disc the last time I asked that question, not sure if I'll be able to find the link now