I have an an old stereo mic preamp in for repair made by ART. Turned out the issue is a dual 5k log pot with a small footprint that I cannot find in any of the usual places. Looks like it was specially made for the product, and no manufacturer markings on it.
My heart sank a bit, as my past experience has been that getting "special" parts from OEMs is often a hopeless task. but anyway I shot them a mail.
Had to chase a bit, but eventually got really good response, super friendly service, and a very fair price from them. Really a nice company to deal with, and they are looking after their old product owners.
I know something like this should be the norm but it is not. Many manufacturers won't release any schemas, give any tech support, and requite you to send stuff to the Kingdom of Far Far Away (if you can get it fixed at all). Real nice to see a company that takes care of the little people, and it deserves a shout out.