You one lucky dude dakota, I've been looking for one of those for a couple of years. Of course they don't make them anymore, the problems you run into with converting those AC devices is the current draw. It's quite high with 12v but twice as bad with 6v. I have a 500w continuous 12v Whistler inverter that I could power up the tube radios with when I was into radio collecting. My jumpers were #8's to the 12v battery. If that had been a 6v with that output capacity it probably would have needed battery cables to connect it up to the battery. Most old radios would have drawn from 100w to 300w power.
I'd love to see what was inside that 6v inverter. It was probably before the solid state divices came along, so there had to be some kind of vibrator built into it and it's probably mostly transformer.
Denny Graham
Sandwich, IL