The V series are in the Studio 2x12. Since I will run it with a 20 watt amp, I do not need 140 watts of speaker in there so I want to pull them and put them in the 1x12s. That said, the 6505 could benefit from a brighter speaker, the V30 sounded better with it (tried it external). So... if I am changing out the Sheffield amd have new V series 70 watt speakers avail, it made sense to me to try one with the 6505 amd use the Sheffield in a 1x12 likely mostly used again with one of the 20 watters. One 1x12 with V series will go with 6101 combo.
But I will try all combinations while speakers are still in their respective cabinets to make sure what works best. I may leave the Sheffield in the 6505. Never having tried the GB, I can't say it's characteristics and what it might suit best. Also I need 16 ohms, not sure if they make that, and preferably over 60 watts.