<VV> More ethanol problems? Limited Corvair

[Grant Young]

Hi all,
I am trying to help a classic car friend who has had unbelievable problems with his 1964 Rambler 232 that has a Carter 2-BBL WCD carburetor. He is on  his 3rd accelerator pump that starts to stick in the pump bore after a week or two of use. Our theory is that the leather pump cup is swelling up due to something in the fuel (ethanol?). The last one was so bad that it actually "curled over". The pumps only come assembled; the same as our first early 60's rubber pumps for the H model carbs. I can not find a supplier of a rubber or buna cup or pump. Even if I could find the right size cup, the chances of a modification don't look promising. This is a significant problem as it gets so bad that the pump sticks down and keeps the accelerator lever from closing (he can cruise at 45 mph without using the pedal) and the problems associated with that. I am checking to see if anyone else has encountered this problem with a leather pump in one of your other classic cars and to see if anyone has any reasonable suggestion (he does not want to trade for a Corvair) on how to overcome the problem. We have considered trimming or sanding the leather cup but this could be an expensive trial and error experiment as the pumps are over $12 each wholesale. We have also considered a different style carb, but he would like to keep it stock if possible. 
Thanks for any insights
Grant