well the watch is a back and top loader. i use a blade and a 20x eyepiece to fine the 1/4 moon on the back that lets you work on the movement or to remove the hold down screws . and there is a 1/4 mood spot the the crystal rim to take the whole unit out.
i bought this watch for $10.00 do to the guy could not open it up. and all it needed was a home, the gold case clean and the release of the over wind. it has a 11OS movement in it and is from 1964 ( M4 )