I bet the reason that Steele does not think they are the same is because the Master Parts Catalog has to list them as different assemblies. All the parts in the assemblies are the same, except for the 12v bulb from 1955-2nd series onwards. So, the almost-identical 1955-2nd onwards 12v assembly has a different part number.
Added later - I think I am wrong on this. It looks like the assembly changed in 1955-2nd. The assembly should be the same for 47-55st
Last edited by tclederman; 08/25/2014 5:28 AM.