The metal adapter brackets for the NewerTech MaxPOWR G3 Cards use a short IDC jumper cable from A/V card's DA-15 connector in a set-back position to match up with the a connector on the backplane of the NuBus Slot'napper assy. Bottom or side mounted HPV Card can have the VGA adapter attached and an HD-15 jumper cable connector lugged up to a DE9/HD15 backplane cover plate . . . du'oh . . .
. . . better, one more step complete!
Atop the standard Slot'napper assembly with A/V Card and jumper cable is one of my MAXpowr G3 Cards with the backplane plate from the Panavue 1bit TPD card/19"CRT combo I bought for my first step up from the periscope on the SE/20/Radius16. Original IIx/Radius Rocket NuBus workstation setup was TPD over DE9 and plate's installed to go into my last NuBus Workstation, the Radius Clone.
Bookmatched bookends for the NuBus era, still have the Rocket33, though the IIx and Monitor went down the storage room whirlpool almost two decades ago.