You don't elaborate whether your crank is alloy or steel. I've only seen photos of the alloy version. I have experience with the steel version, one of the most beautiful cranks out there, in my view.
For the steel version the BCD is 116 which was a popular standard for racing gearing in the 1940's and 1950's.
At the time Simplex and Magistroni were the dominant players in italian racing crankset components. Gnutti a step below with regard to market penetration. I know for certain that a Simplex 3 pin chainring set fits a steel campagnolo 3 pin gran sport crank. Magistroni should work but I don't have confirmation on that point.
Chainring sizes for 116 were typically between 49 and 53 for the large ring and 43 to 49 for the small ring. I haven't seen single chainring setups but there is no reason to doubt that it couldn't work. Or carry the extra ring and manually shift onto the big/small ring as conditions warrant.
I might add with the rather small differences in ring size, a stiff chain from that era combined with period correct derailleurs gave a shifting experience that is excellent.
Good Luck,
Todd Teachout
Hercules, CA