PX72 Adapter (Flashbattery) for 15x AG9

a bit primitive, but it works
Print it out
Fill 15 cheap AG9/LR45 cells in
Fiddle the whole thing in your historic Flashgun without loosing the buttoncells.
Congrats, you have a working 22,5V 72PX Derivate

an shorter adapter (49mm) for 14 button cells added