Ok had another go today and I’m going to wait until the other collets arrive. I managed to find 3 in France that I bought yesterday and are currently in the postage system.
I got a good pivot on the one I did this morning but there’s no way I can do the other pivot until I can turn the job around and hold it in the smaller sized collet.
So it’s a waiting game now, so I’ve a few Balance staffs that need changing so I’m going to get on with them for now until I can carry on with this job.
You might also like to take a look here -> https://17jewels.info/movements/a/as/as-1951/
The one you have looks filthy and I would also suspect from the position of the balance regulator components, that it is out of beat and running slow.