I can sell you a carb-kit for a 57 Studebaker, I guarantee you it is made with ethanol-proof parts.
It costs $100.00 to replace the diaphragm on my ATV.
I guess, just junk it then.
My cousin told me about his old, 50s, that when he lets it set for a while it will not start and does not run right as the low octane form the evaporated alcohol. I suppose you would want to junk all vehicles that are over 10 years old.
Carb rebuild kits aren't usually a problem, those can be found with ethanol-resistant parts. Same thing with soft fuel lines - just use the Gates "green stripe" hose and it'll last. The bigger problem now is mechanical fuel pumps. Might have to switch to an inline electric pump to prevent ethanol-related problems.