Most people use the 205/75r 15, but the 215/75r 15 is very close. see the second chart down (white chart) in this link https://www.turbinecar.com/tires.htm
Ive been thinking about going with Radials as well. I found a company in Sacramento cal called calli tires. They actually volcanize there white walls onto new radials and have them in several white widths as well as a lot of popular tire sizes. there prices are really good. callitw.com
Lower priced radials will have a narrower section width that pairs better with the shallow 1952-54 Ford wheel wells https://www.pepboys.com/cornell-1000/product/9378320 then are these tricks https://www.youtube.com/results?search_query=shaving+whitewalls