I had a carb. corroded like yours and I broke
the casting trying to get the sleeve out.
Never did. You may have better luck than me.
Those coils are not usually bad but everything
in that magneto need to be set just so for it
to work. There people that post here that
understand them. I’m not one of them.
Tubs.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.