Seamaster 120 Missing Bezel - Value?

A friend of mine says he has what he believes is an essentially original 120, but w/o bezel. Crystal he believes was replaced sometime in the early 00s.

I'm trying to get some images from him asap, but as he's selling it, if he's correct otherwise and it is in fair condition cosmetically/good mechanically, but still missing the bezel, anyone want to venture a value/worth guess unseen? Repairs for one this old aren't my forte, but I also don't want to just say no to it and later realize he got ripped off by a pawn dealer or something (he's definitely not a watch guy, and I'm still new to anything older than the mid 80s).

Thanks for any thoughts, and again, sorry for the lack of pics.

There are a few SM120’s. I am guessing this is the 165.027 but if it’s another such as the 165.025 replacements are available