Q's re '82 Black on Black Sub

[Pro2ndAm]

My wife took a Sub from a local jewelrer home for viewing and I'm seriously considering buying it. But I know nothing about Rolexes and the jewelrer was not really knowlegeable about Rolexes nor did he have the inclination to find out or vouch that it was a genuine item.

Fortunately, I found this forum and was hoping to get some feedback from the vets on this board.

There are no box or papers, other than the green sticker on the back of the case, bearing the serial number. The serial number begins with 72767 and it appears the previous owner never wore it. I was told it sat in the safe for almost 30 years other than servicing--but no history provided.

The asking price is $4,500.00 cash and I have to give the owner a response by tomorrow and any advise would not only be welcomed, but appreciated.

Soon to be Sub owner in CA

p.s. Still trying to figure out how to upload some pics