The early ignition days did most likely originate the power pod concept, but that was way way before my time. You mention the Aircore series which had the radio installed on a "cartridge", as I recall they always had patent pend on each of their ads.
However, if you go back to the late 60's there was a parasol class II design presented in Flying Models around 1967 or so that used that concept. It was designed by one of about three prolific designers not name Ziroli. Bryon or Bruce Peterson I think without looking. I was always amazed how many designs came out of a small area in Massachusetts ever month.