Maybe this can help ...something new I did up a few months ago..(ok I actually took over 2 years of research and development to make them!)
This was a completely new design of the older VAG calipers I did....based on the current GOLF or AUDI A3, A4 , A6 ...
This is the Quattro version (with 38 piston)
Here one of them mounted on an Audi 100 quattro.
These things have dual o-rings for better water intrusion....I designed them to last A LONG TIME!
And NO they do not cost an arm or leg...I offer these at less then 1/4 price of VAG...plus I throw in new brackets and pads.
Where to find our more about these things?-->
http://homepage.internet.lu/customautocraft/typeB2_80_90_4000.htm#BRAKES