I'm in New England, so a trek to Nashville would be a stretch.
I have used the A12, (along with N72's, J9'9's, C84's and a DI) for years and enjoyed excellent experience with each flavor -- in fact, did an unusual pairing of this particular A12 with a Schoeps CMC621 microphone in a tracking demonstration two weekends ago. My clients are increasingly asking for tracking of strings and string ensembles which is leading me to want an additional C84 and J99 modules - hence my interest in freeing up a rack space (the A12) and in your C84. This A12 module has been rock solid. No issues whatsoever.
Do you have an old rack or one of the newer ones? (The A12 I'm offering also includes the faceplate for the newer SCA rack.)
Since you don't know the history, I would be grateful if you could email me good good quality photographs of the front and back of the module. (Just take care not to touch the components without wearing a ground strap and avoid placing it on something like bubble wrap that would harbor static electricity... ) I'll reciprocate with photographs of my A12 and we'll decide how to proceed from there.
Email:
HerbArcher3@gmail.com