Hi , take a look on my mods of the c521 here:
http://www.homecinema-fr.com/forum/v...php?t=29849689
(it's in french but with photos )
In place of your mcap i've put elna silmic II on coupling +mkp+silvered mica etc...(details if you want ),a new clock , new AOP LM4562 ,9400µf for the 12v supply , glue on the bridge like you , and in future new supply with LM317
for each section (i working on it ).
Advices or questions are welcome
Regards