Rolex 1602 strange part question

[SwissSeiko]

Hello all. I'm working on this Rolex Cellini and when I was removing the retaining ring, this small, strange screw came out. I can see where it goes, but I have no idea what it does. It has a rectangular slot cut in in, and it sits next to the retaining ring, on a post. I haven't disassembled the watch yet, just checking if you guys have seen this. There is only one of these, and it's not a dial retainer.

[AndyGSi]

28 minutes ago, SwissSeiko said:

I can see where it goes, but I have no idea what it does.

So where does it go?

[oldhippy]

That is the head that has broken off. normally those screws would be for holding a ring that goes around the movement or they would be for holding the movement in its case. 

[SwissSeiko]

2 hours ago, AndyGSi said:

So where does it go?

Sorry, it sits on top of this pin

 

2 hours ago, oldhippy said:

That is the head that has broken off. normally those screws would be for holding a ring that goes around the movement or they would be for holding the movement in its case. 

That is what I'm thinking too. It looks like it broke off perfectly, leaving a slot in the screw head.

[AndyGSi]

You'd normally have a case clamp in the recess.

[SwissSeiko]

8 minutes ago, AndyGSi said:

You'd normally have a case clamp in the recess.

This movement is double clamped. It has the clamps above to hold the movement spacer in place, then the above broken screw to hold the movement to the ring. Its set up almost like it can be removed from the front or back for some reason. This movement is only used in the Cellini, so I'm not sure why they need a spacer ring to begin with...

Edited January 22 by SwissSeiko

[AndyGSi]

7 minutes ago, SwissSeiko said:

This movement is double clamped. It has the clamps above to hold the movement spacer in place, then the above broken screw to hold the movement to the ring. Its set up almost like it can be removed from the front or back for some reason. This movement is only used in the Cellini, so I'm not sure why they need a spacer ring to begin with...

I think it's the fact it's derived from the 1600 which was used in a lot of other Rolex.