Thinking you may be missing a digit in the S/N. I have an AV DeLuxe in 375 from the same era with a 579xxx serial.
If they intend to shoot it they should check for the presence of a bolt guide cross pin. In the pic below it's the small pin immediately aft of the blue bolt collar.
Without the pin recoil will eventually break the leaf spring and tie up the action. Don't ask how I know.

[Linked Image from i.imgur.com]

There is nothing made by man,
which cannot be broken by woman.