Diameter of motor pulley for 1952 FP-1?

Could someone tell me the proper diameter for the motor pulley on a 1952 FP-1.

This machine that I'm restoring originally had a 440v motor. I was able to locate a 220v motor from another early FP-1 that looks identical except for the pulley diameter. Either pulley will "work", but I would obviously like to use the proper diameter.

Thanks for the help,
Gaylan