Yeah, we called it the G80 without even really knowing that was Chevy's RPO code. RWD Volvos (like that 740) use a Dana 30.
I don't care much for welding parts to the diff like that, I prefer to chop that weight off rather than add something to keep it in place.
That's funny the Gov-Loc came to be known outside of the GMT400 world as it's GM RPO code. Better to just call it the Gov-Bomb and be more technically accurate.
As to the question whether a 9.5" 14 bolt ever came -without- a Gov-Loc, absolutely. I keep a file of old SPID label pictures from previous parts trucks and found several that were 9.5" 14 bolts, both with and without Gov-Loc RPO's. I've got a couple 88-89 C2500 6 lug 4.10/no Gov-Loc, 91 C2500 8 lug 4.10/no Gov-Loc, 94 K1500 6 lug (F44, aka "heavy half") with 3.42(!) with Gov-Loc ...
So yeah, they're definitely out there, just luck of the draw. And, whether you can read the SPID label or not (sketchy on 88-94 models due to sticker placement) and if the thing has been swapped out or not in its past. Pull the cover. You wanna know the condition of it anyway.
Richard