Delighted to have picked up a 7 volume set of these books for £8 at a car boot sale. Of course the highlight is the section on Simson.

Streetfighter brake pistons

Got 5 of them out but 3 stuck solid. The issue is oxydation in the grooves for the seals and in the chambers seizing the pistons solid. Tried freeze spray, heat, you name it but no joy with these. Plan to send away to have these removed and all new parts fitted.