The problem with the 200 and 300 series is that they are so smooth and quiet that even though this one is an aesthetic disaster it functions beautifully and had to be saved.
One of the reasons I like going thru these old machines is just how much I learn about the dozens of ways things can and do go wrong.
I left the hook assembly until last, thinking that the slow spot was in the main gear. It turned out that (under closer inspection) the bobbin case was from a different machine! Almost identical except for one detail, I ground down the offending difference and all is fine.
I am completely sold on rotary hook machines and although the Bernina 830 is not you won't find many other systems work better.
The worse cosmetic feature is the large paint chip on the top cover. Otherwise I'll be making a base for it soon