I doubt you have anything to worry about.

A Nitro is a brute. I've seen a bunch of those that look like they have spent the last 80 years in the bottom of a duckboat, and the owners were still banging away with them. There was also the article in DGJ about the similar condition Nitro Special 12, that was off the face to boot, repaired with brass shim stock, fired for 20 seasons with heavy duck loads, traded away, and still being used like that.

Best,
Ted