The nomenclature 108G means 10"-8 ohm-Guitar. I believe they were all AlNiCo, a small round magnet surrounded by a U shaped frame would verify that, if so they are rated at 40 watts. Probably late 70's/early 80's Hartzell era, based on your code I'd say 1982. I think Sunn was actually producing their own drivers then, but they could be CTS.
I had a quad of them in a Sunn Beta Lead combo amp, they sounded OK in the open cabinet.
I'm not much of a guitar player, but there is a faction who are huge Beta Lead fans, and those AlNiCo 10's and 12's were in most of them.