That chassis pic is cool. Except I can't figure out what makes it go. I don't see a chain or a driveshaft anywhere. As far as sitting on the engine, no different than a motorcycle. In fact, that's what it is, three wheeled cycle, swing arm rear suspension, springer front. I had those same drum brakes on my old Yamaha, they stopped just fine, especially since the whole thing probably only weighs 400 pounds. It has to have a pull start, no room for a kick start. I wonder if that thing sticking up in front is the rear brake lever, or maybe the shifter. What's old is new again, these guys just put the two wheels in front:https://sp.yimg.com/xj/th?id=OIP.Mf904221f152bd2e96124ace880f07b42H0&pid=15.1&P=0&w=300&h=300