This is a c1920s-30s vintage R. Its overall measurements are 11.5cm long and the screw thread measures 2.7cm long and the badge measures 6.5cm wide x 2.9cm deep.
C1920s-30s ROYAL AUTOMOBILE CLUB MOTORCYCLE SIZE BADGE No MCA2834
This is a c1920s-30s vintage R. Its overall measurements are 11.5cm long and the screw thread measures 2.7cm long and the badge measures 6.5cm wide x 2.9cm deep.