hoghead, make sure that acid doesn't remove the black hard anodizing in the piston pockets. I would test something else that is hard anodized... just to be sure. If the anodizing is removed from inside the piston pockets, and you rebuild your calipers, there is a chance the heat from using the brakes can cause the pistons to stick. The anodized finish can be powder coated. If your calipers still have factory anodized black w/clear coat, it is very easy to remove just the clear coat, and leave the anodized finish.
I would be very interested in your findings on seals (and of course Zen too). I might need some for future projects
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1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans
1962 SC 1776cc SP 944NA brakes, 993 wheels
VKG