I have some limited information
From 1969 to 1979 Chiyogi Asahara work at Sanyu Glass. There is also a book about his glass out there but I have not been able to locate a copy.
Also, Kunitaro Uchida began studying at Sanyu from 1968.
From 1972 a Katsuhiro Kageyama joined the company.
I am not able to tell who may done the piece though
But in the future I may be able to as I am gathering contact details for these glass artists.
Hopefully soon I will be able to detail Sanyu Glass Company a bit better for everyone