I'm no expert but I can't see anything wrong with the case/dial/handset. The twinlock looks original (if it's not, me want some)
The bezel insert might be recent or aftermarket but it doesn't detract.
I'd love to see a picture of the caseback (inside and outside) and the movement, though.
Are there many differences between ND and Phong cases? I remember ND being cheaper at the time.
Anyway I went through this here
The end result is virtually impossible to recognize. I should know, I had it serviced at a Rolex AD. And that was before I work the CGs.
Since then I built another one, still have to do the CG but it looks promising. I'll try to show you pix soon.
Hope this helps