The controls for the cam stack selectors that slide up and down on the two vertical rods just left of the cam were stuck. After working on my first 500 I had no intension of slaving over that little problem. So I took a small bottle with a long metal spout and filled it with Hoppe's #9 gun cleaning solvent. Dribbled it on the stuck parts then went away and did something else while it soaked.
Came back later and they're all freed up. I have the machine oiled and greased now and it runs sooooooooo nice. Next a thorough cleaning.
After that I'll see how it sews. If it's good, it's gonna be real hard to flip it. I might have to flip a different one.
Joe