I have found a simple solution.... I fill the nearly empty tank with avgas 100 before my 1969 E-type goes in for the 6 month storage. The fuel is cleaner, has no alcohol, and has a little bit of lead in it. I also use the same stuff in my chainsaws, etc.
The mandate for gasohol is ruining more machinery and thus, contributing to waste and damage to the environment than it is perhaps saving in pollution.
Good luck,
Josh