This particular watch had a couple of odd issues right off the bat.
We can see here the outer regulator pin is pressed closed, over the other pin, such the the regulator can not be removed from the hairspring.
Also note that the upper pivot is a bit short. At first I thought it was broken. But I am not so sure. The staff on this watch is not the original part. It is a different staff that has been rigged to fit. It looks like the upper pivot was shortened.
These watches originally took one of two staffs, which are quite different from each other (and both hard to find). Since this watch does not have the original, it's hard to tell for sure what configuration it had. It's also very possible that the entire pallet was raised or lowered to made the replacement staff work.
The regulator is not in place in this photo, it doesn't have its new pins yet. But we can see, at the upper left, the bar that reaches in to hold the outside end of the hairspring, below the balance wheel arms, rather than above like most of the watches I have posts about. On this watch the hairspring is below the balance arms.
Watches like this are closer to English designs of that time.
The next images show the regulator is in place, with a pair of new pins. There is very little clearance, and everything has to be just right to work well both dial up and dial down. It's easy to see why this design gave way to placing the regulator on the upper side and pinning the hairspring to the balance cock.