Stephan Gellerstedt is a graduate of Konstfack in Stockholm. In the
1970's he designed for Pukeberg Glass Works.
After leaving this glass works, set up his own studio on a ship docked
in Southern Stockholm across from Gamla Stan where his work was
featured in a gallery. I visited this studio in 1990.
I have not heard of his art glass since my return to Sweden in 2004.
This bowl reminds me of his style.
Best
Bill