It turned out to be an InStep trailer in fine condition except for all the fabric, which all smelled like smoked dog poop. I stripped it down to the frame, then made a wood base from an old pine Lundia shelf which used to hold toys in our store and had previously served in a local Pier 1 store. The fabric sides are made out of canvas Bananagram swag bags we got from a vendor at a game store conference.
After a couple hours work and $0 spent, the Bananwagon is complete. Possibly my finest work of creative reuse in 2018.