I had been looking around for a tutorial and found this one on the Knitting Circle. I am assuming this is the best way to freeze the chrono hand on the 23j watches with Chronos. Those movements, from my research, are DG3836P. Available on CousinsUK here:
So if you screw it up, you can get a new movement pretty cheap.
Here is the post from the knitting circle:
Freezing a Center Seconds, 3 & 9 Subdials, for what could be a reliable Center Seconds Daytona. (But non-working chrono, so appearance only)
What I found, and it can be done....
CAUTION - Working on this movement requires a similar skill set to working on a 7750. The Auto-Winding assembly was never really meant to be disassembled on this otherwise 'disposable' movement.
Pics to explain it all:
Now put the winding bridge back on.
I'm going to try this soon, @GenTLe is this how you would do it? I've had crap luck putting winding bridges back on 23j watches. So I may well destroy mine in the process but you gets lots of tries to get it right.