I would of recommended QI wireless charging but then buttons wouldn’t be accessible.
I’m ok without a battery since you can plug into just about anything including smart phones to share power.
As did I with the same research except didn’t find original prices. All I know is at least 2 prototype of Panic bomber exist because he has an extra one.
Here is a more updated view of my collection. You can always view my profile for more info or ask any questions.
I sold all my homebrews except insecticide and the re-programmable carts.