It has some simularties to a Moss Cart the steering wheel and linkage and pedals, mine doesn't have a cage around the motor it was set up for two Macs with the gas tank on the back of the seat
You might try posting that picture on the Rear Engine American Racers website. they're all about 60's style karts. Someone there could help you out. That's a cool lookin' rig, by the way. Your daughter will enjoy it!! Pluck