I believe that ethanol can react with the rubber pipes and seals on older cars causing them to fail. Newer cars shouldn’t suffer due to better materials resistant to the ethanol.
Remember, ethanol is a hydrocarbon solvent so can react with materials it comes into contact with. This is in addition to the hygroscopic property.
When I flushed and refurbished the fuel system on my 1993 Morgan I replaced the flexible fuel pipes with modern ones, including a Bosch pump that was described as ok for ethanol resistance. I used 95 octane in that car.
My thoughts for a Morgan are...
How old is it and what condition are the perishables?
How much mileage/ how often is it used to make sure fresh fuel is in it?
I do wonder at the effects on the many older Morgans with, for a car, low mileage examples that come up for sale. Visually they can look pristine but age causes hidden issues.
