Ladymatic 681

I have a couple of these in the queue to look at. Curious on the 681 movement it is a screw. On the 684 it is a button. I have not yet looked opened the Geneve dynamic which has a split stem. (The new stem and crystal just arrived last night.)
I guess my first question would be with such a short posting history, what are your qualifications? Do you have a watchmaker? This sort of watch is not for beginners. Watchmaking is the sort of thing that can not really be learned from books or amateur instruction videos. One really needs a mentor.

I would recommend getting some Benruses and practice on those. Get a few 10 ligne or more and practice taking them down. If this is a one off, please have a qualified person do the work.

Also photographs are a must. Here is one I have of one of the 'triplets' I recently got on ebay. This did not have a stem. So I was testing it with a stem and crown I had in my omega spares. The crown is obviously incorrect, but it fit the stem well enough for a cursory test.