Rolex GMT Master with unrecognizable serial number

[Bond's First Watch]

A local gal whose father was a jeweler (and has since died) is selling a 1992 Rolex GMT Master. The watch is in decent shape for its age, but when she removed the bracelet, the serial number of the watch is completely unrecognizable. To me, it looks as if someone intentially obscured the numbers, which makes me wonder if the movement is original as well. Her father had written down the movement serial number, bracelet numbers, etc.

I'm thinking purchasing this watch, even if authenticated by another jeweler, is too big of a risk. It's sat in a jewelery box for 10 years and would require a complete service too.

Thoughts?