i have a c with the alloy arm that has the brake lug on it its one of the first 30 from the start of the c numbers ,it has the floating backing plate,and arm conected to the frame
my c swing arm that came off the first 30 frame numbers has the lug and needle bearing.the other c swing arm i have came with bearings or bushes removed but they look the same size .i cant see any differance
i have two of the 125 alloy arms with the brake lug on them one i got in a parts lot that i bought and one came on a early model c that i bought ,the owner of that bike had it from new its frame number is one of the first 30 from the list of frame numbers for the c