maybe you had them longer up there than in the states? from what i've seen most yardlights had the short clear ones by the end of the 90s. only the true NEMA head kits still include a name brand PC and name brand lamp. GEs supply GE lamps (obviously) and ALR PCs, AELs have Philips lamps and DTL PCs, and i'm not sure what coopers have...
The guts are pretty much the same in both. Do you mean the shield is different? (the metal piece in front of the photoeye.) FP used a few different versions of those metal shields from the 70s through the early 2000s. They just seemed to use "whatever" lol.