To my eyes, your most recent photos are BG x GSF hybrids. I agree on the "10 inch" photo showing a bluegill.

HBG could mean a lot of combinations, but most often it is used to describe a BG x GSF.

"Forget pounds and ounces, I'm figuring displacement!"

If we accept that: MBG(+)FGSF(=)HBG(F1)
And we surmise that: BG(>)HBG(F1) while GSF(<)HBG(F1)
Would it hold true that: HBG(F1)(+)AM500(x)q.d.(=)1.5lbGRWT?
PB answer: It depends.