More than likely the route I will have to take, but was looking for some in like new condition to match the restoration to be one less thing to do. All signs point to none being in existence, and all the remans I have found (including the ones I bought) are incorrect, and for the earlier 2800cs or E3 with solid discs. The rebuild kits are available, and ironically, I sold the BMW OEM rebuild kit I had.
I agree, with the correct fitting, the grease gun method is effective at getting those pistons out. Really, not many parts involved, unless you need new pistons. I see RMeuropean lists E9 caliper rebuild kit, and also still available from BMW.For those of us without good luck or a compressor, don't forget a grease gun fits perfectly with the bleeder holes and can handle any stuck piston, just need some brake cleaner after to clear the grease.