I'm in the process of rebuilding the front calipers on my 1969 BMW 2002, vin 1663275 built September, 1968 (two piston type). I had to disassemble the caliper halves (due to a very frozen piston) which I know is discouraged. I have found the correct high strength bolts and nuts to reassemble the halves, but I can't find the two little seals that go between the halvs. They look like small fat rubber washers... about 9mm OD and 4mm ID with thickness of 3-4mm. Any ideas on where I could find these? Thanks.