Sometimes the best thing is knowing who NOT to buy from... And this is one of those sellers. Claims her husband was a recording engineer and carefully words her listings to lead you to believe she's selling a professional recording.

This turned out to be a 7 inch reel, 1/4 track tape recorded in mono at -10dB and with a high noise floor. Probably one of the worse sounding tapes I now own. Actually this 40 year old tape is worth nothing, and the plastic reel about 5 bucks. What's even worse, is they instantly copped an attitude when I asked to return it. After writing GREAT SOUND several times throughout the listing.... I found out that they auditioned it on a pioneer receiver hooked to a pair of bose 601 speakers... which didn't help their case. It's possible (-10dB recording) that this was partially erased by a nearby magnet at the post office, but neither ebay nor the seller gives a shit, they both got their money.
You're going to run into this buying tapes, it's a learning curve, so cost of mistakes have to be factored in.
I'll be taking it to the range this weekend and using it for target practice so I get
some satisfaction out of it.