No info on it other than the pictures. Should the caseback not have some design on it ?

 

Should have the Seamonster on the back, plus case reference, and likely "Tool 107".

 

I read somewhere that older ones didn't have anything on the back. Or maybe some have polished caseback ?

 

OK

 

Here's some quick and dirty shots of a cosmic I have. "Seamaster" w/ the Seamaonster, reference# and Tool 107 engraved.



But the case you show there could be engraved it's just horribly out of focus.

 

Not uncommon for the logo to be worn or polished off these, they weren't very deeply stamped.

 

yep - and def. not a watch easily/often faked ...

they are cheap to boot with ...