Well, my interest is in all early Studio Glass, so that encompasses some American; all the early work and artists at the RCA (Sam Herman in particular); Harris "dynasty"...
include Peter Wheeler at Wfs, but simply cannot afford the prices his work goes for. I'm still waiting to find a bit of Peacock hiding away at a reasonable price somewhere.)
There were other makers in Europe branching away from large factories producing "perfect" pieces... basically, the Studio Glass Movement was similar to the Artsand Craft Movement much earlier on.
Benny Motzfeldt was doing this in Norway, and Erwin Eisch was "doing his own thing" in Germany.
I have even discovered there were similar things going on in Polish factories in the early '60s, although the makers/designers, such as Felixs Nawrocki and Zbignew Horbowy, had the use of the facilities of the factories there and the blessing of their bosses to do be doing it.