My 'stenbock' is signed: FM Ronneby Sweden G7 - 220
The inscription indicates the size 220mm but mine is in fact 235mm.
I don't know who designed them, I've yet to find out who "G" is.
They have been available in different sizes over the years:
160, 220, 250 and 280mm.
The label " Handiwork FM Konstglas Ronneby Sweden " would date
the 'stenbock' to approx. early/mid 1970's.