Batteries
You can still get some of the B batteries, although you have to pay dearly for them, somewhere around $30 a pop. On the other hand, I built mine. The A batteries are nothing more than modern #6 cells with vintage covers on the outside. The B pack is really one large masonite box--it has grooves cut into it to give it the illusion of four separate B batteries. For motive power, I have a DC-DC converter. You put in 6 volts, it'll pump out 67.5. Add another 1.5 to the mix and it'll give you 90.