They're from 2 different eras, but I can't tell exactly which ones for sure.

Drumaholic,

Thanks for the critique. When you say "sometime later" do you mean later in the same era or like a decade or two later?

Maybe someone tried to make a kind of NewBeat pair. They have a larger than normal top bottom differential. I've played quite a few pairs like this over the years and some of them have been terrific.

I've never really understood the term "factory matched pair"----aside from the fact that this confers some sort of cachet to the cymbals that usually means that they are worth more. Just who in the factory paired them and using what criteria? Were they paired because they were exactly the same diameter, because one was exactly 40 gm. lighter than the other, one was exactly an f and the other a g or was it because they had the same lathing or were they made contiguously? Is there a guarantee, that some cymbal matcher in the factory is musically inclined enough to know how to match them for whatever uses an individual professional drummer might require?

The one in the left appears to be mid to late 60's, and the one on the right is from sometime later.

Maybe later 1970's or early 1980's if it has the 3 dot trademark.

It used to be Robert who did that, and he seemed to to a very nice job.

But I think most of us here could probably do as well. I've seen mixed pairs matched by drummers who custom matched 2 of their own, and they sounded geat.

Mine are all mixed and they all sound awesome. (in my opinion)

i agree mid to late 60's and early to mid 70's