Most likely your source has to be ebay and from Europe.
I live in Europe and have used ebay for parts for my B77 with success.
Revox A77 mk2
I have 2 Revox A77s purchased in 1970. Can we still get parts for these decks from Revox/USA in Nashville, TN? If not, where in the US is a good/reliable source? I'm looking for complete circuit boards, in particular, the Record Ampl. board 1.077.705 and Oscillator board 1.077.712. I've checked with Revox On-line and Ebay but both sources require shipping from Europe. If there's no US source, has anyone had experience using one of these?
Thanks