Ours was a lot less elaborate. No double-wall spoke wheels, just clunky steel rims. The outers were gone and it wasn't obvious if it was wooden or rubber wheels, though I suspect wood.
The chair mechanism was a wooden hand crank, though we never cranked ours due to rust. I didn't want the chain or gear to snap. Basically just a crank with a small gear that drives a larger gear.
It couldn't have been easy to crank and you certainly weren't going anywhere fast but as a wheelchair, back then, speed was probably not the goal. I'm sure downhill was a breeze
