Michael:
I wasn't suggesting that my made in Canada piece was by the same maker as your piece. I'm very confident they weren't, in fact. But they are both roughly spherical with push-ins. So we have the same technique in John's Sarpaneva piece, your piece, my piece, some Czech and Japanese pieces you've found, which points to the fact that it's not an unusual technique and has been used widely used. I think your suggestion that it's 1970's studio glass is a good one. I wouldn't trade it for a Skrdlovice piece, though.
David