I bought a couple of 65s secondhand, figuring I'd keep one and flip the other. The one I "knew" at least had to be gen arrived as a 42mm instead of the advertised 40mm...which now leads me to suspect them both. For those who had a gen and a rep side by side, what differences were there? Or, failing that, can anyone tell me how serial numbers on replicas work? Do casebacks on these medium-level reps have unique serials, or are they all the same? The green 42mm I received has a different number than the one pictured in the thread...