Resurrecting this old thread...
I had some time and took another look at putting the BA II on my JetGlo 4003. I made a small filler block out of a piece of maple, spray painted it black, and installed it using the existing screw holes. Then drilled 5 new holes for the BA II and installed it. I was a *little* hesitant to drill the new holes, but all of them would be covered by the original tailpiece if I decide to go back to that. I have a plastic surround piece, but it doesn't fit well, so I'm having Pickguardian make a new one for me that should arrive soon.
Intonation and setup was easy and no issues with the BA II so far. I don't think it "helps" in any way, although I would say that intonation was easier. And I will need to drill some new holes for the plastic surround. I may just use some double-sided tape for a while to make sure that I want to keep it before drilling the screw holes for that.
Thank to everyone that provided pictures and other helpful information!
--jack