Very interesting. I don't know much about how efficiently an automobile engine could burn alcohol, but it would be interesting to compare gasoline and alcohol at the posted prices in terms of cost per mile. Arguably, the gasoline might have been cheaper.
Hal Davis did the test in 2011/2012, he drove his TT for a whole year on E85 alcohol: http://www.mtfca.com/discus/messages/257047/297694.html?1341064408
He reported 79% mileage on alcohol compared to gas. The price in Cuba of alcohol was just 52% compared to gas, so the alcohol was indeed cheaper to run on at those prices - you could even mix in 15% gas as it is in E85 today and still be ahead.
The price difference today over here is much less, so almost noone buys E85 at $4.94 per gallon when regular gas is at $5.40.
Seems I remember that formula race cars ran on alcohol. I watched one race where the fuel caught on fire but couldn't be seen as alcohol burns clear without smoke.
In the sugar cane plantation regions of Brazil, they have developed a clone of the Piper crop duster planes of the USA but with engines that run on alcohol. Alcohol is dirt cheap there and is distilled on the plantations from the same sugar canes they dust.
Strangely enough none of those engines have been displayed at Oshkosh yet.
It's not rocket science to alter an engine to run on alcohol - it needs more alcohol in the mix with air, so with a carburetor you need a larger main jet. Easy with a T, just screw out the carb control a little.
Alcohol will dissolve shellack, so cork floats needs to be covered with some epoxi that withstands alcohol instead. As long you're driving mostly in fair weather, nothing more needs changed, but the efficiency of the combustion would be better with a higher compression ratio than is used with gas. And if you want to drive when it's freezing cold, it'll be very hard to start without an engine heater.