The earliest Wisden I can find is October 1983.
I'll post a few pics from it another time, but........
Romida Sports of Oldham in Lancs advertised the GN 100 5* Probalance for £54.40 with a RRP of £67.99. That was the top of the range model. Others included; Superlite, Supershort, Powerline (with a nylon covering so I assume that was a G3 at best).
GN 100 5* Pro balance is a typo:
The GN 100 was the scoop range
The GN 500 pro balance was the 4 scoop range
supershort was supershort handle
superlite was short blade and slightly angled shoulders to give a very light bat