If it has been recapped and no audio is coming out… someone has already given up.
That means (in my opinion) you should only buy this if it is really, really cheap.
In the last videos about the Marantz 82 and replacement of the head, you can see how to measure a head… but that requires removal of the mechanism, and can only be done after purchase. What is the asking price?
Fully re-capped and no analogue audio whatsoever is a bad sign imho, well it could be the read-write-board that I am designing a replacement of but a dead head seems likely and in this case it would basically be worthless.