Rain,
I think you can save yourself the air fare. I have had fun with the screw driver this afternoon.
You will be pleased to hear that the 15K is now fixed. All it needed was oil on the shaft, and I feel a bit of a dimwit about not getting it sorted before now.
No joy with the Serata yet. It has nearly a century of black muck welding the balance wheel to the shaft so I can't get it off to clean and oil it. I'm inclined just to leave it as it is. What is interesting though is that there is a lubrication hole in the balance wheel to take the oil straight to the right place, whereas with Singers you have to take the wheel off if you want to reach that spot. Very clever, the Germans. One of these days I might do a video about pre-War German bobbin winders. They are in a class of their own.
Talking about clever Germans, I have two machines, the Little Vesta and a Frister and Rossmann transverse shuttle, that disconnect the motion with a much simpler mechanism, so you have no wretched stop motion screw to contend with. Want to see pics?