At the Seaway meet there was a '51 Henry J that had the same vinyl as yours, I don't remember his name but he was from the Cleveland area, I believe.
His door panels and seats were done in that vinyl. His seats and seat backs were done in that vinyl and pleated. I don't have a lot of knowledge but I thought the '51 Henry J seats and backs had some sort of inserts, either plaid or some other color material.
Don Holt#10019