I've heard that Porsche convertible top cleaner is the best on the market for modern cars. I'm just not sure how the material used for replacement Model A tops compares.
I used a gentle solution of "Woolite" & a soft brush on my canvas Cabriolet top a couple of yrs. ago. Rinsed it with cool water wiped down with a soft towel & let dry in the sun & it came out nice & clean. The top is 40 yrs old.
