I dunno if I'm just lucky but I've had hobbits in way worse condition and all they ever needed was a carb clean and new fuel/oil from an auxillary tank. They both went close to 30mph right away.
Isn't the battery just for the lights/signals and act as a rectifier anyway? If you wanna do the bare minimum to get it running you might not even need that.
Whats the tank condition like? Clean inside? If so, I would just clean the carb and put some gas oil and see if it runs.