New to the forum (typically on diyaudio and audiokarma) and 2+ months late to this topic. Quite a nice dialogue and repair.

FWIW, I went through an almost exact repair sequence in February 2021. I acquired a C325BEE (a for-parts-only special) from ebay.
Although in addition to the +/-18V power supply issues, the main power board was fried on my amp. In the end I have a very nice working amp.
I wanted to add that the failed SMD caps on the CB21 + CB22 riser boards I replaced with similar SMD form-factor parts, but solid-polymer type electrolytics.
Again, I enjoyed the thread, very good info.