Dux Astroman Dome Differences

[Hymie]

I have noticed that some Dux Astroman helmet domes feature a longer/deeper "antenna socket" than others (see photos below). I'm wondering if the domes with shorter sockets are the repros, and those with the longer ones are originals, or vice versa (or even if it might be indeterminate). A lot of the old photos seem to suggest that the deeper socket was original, but I've seen both types billed as "original dome" (I realize of course that you can't depend on the veracity of a seller's description). My Astroman's dome has a short socket, but the plastic has a moderate "amber" cast when held up to the light, which seems to suggest age. And since the antenna easily falls out of the short socket, I'm wondering if (hoping that?) maybe there was a design change early on to correct the issue. Is it possible that it could go either way on both designs? Any insight on this out there in robot land?