My 1936 DeSoto and my 1937 Chrysler Airflows originally had roll-up rear window curtains. The Chrysler curtain was torn, and the DeSoto curtain was missing altogether, except for the brackets. I contacted Lebaron-Bonney about the curtains, and they offered a complete replacement. The steel roller on the original Chrysler curtain was about 1/2-inch diameter, and Lebaron-Bonney did not offer anything that small--their smallest is about 1 inch. The fabric they provided is a very dark brown, almost black, and quite opaque. The size is as I ordered, 36 inches wide and 21 inches high unrolled. I ordered new brackets as I assumed the larger roller would not fit the ones I found on my cars. The charge for the replacement curtains was very reasonable, in my opinion. With new brackets and shipping to California it came to under $65. My only complaint is that Lebaron-Bonney were not able to supply the brass clip that attaches to the slim rod at the end of the curtain, that keeps the shade rolled tight and hooks to the notch in the window garnish moulding when the curtain is pulled up. Still need to solve that.
Note that some Airflows, and I don't know which, had the curtain mounted inside a cover like this:
Assuming the cover was made for the 1/2-inch original roller, I doubt that the Lebaron-Bonney curtain would fit inside.