If you have the U-Bolt front mount, you may find it needs to be bent a little to match the angle of the bend in the front of the frame on the cranbrook in order to keep the rear one somewhat straight, and give your carb a good level.
I purchased front and rear u-brakes for mine for $15. The front ones went on fine (removed fenders) but the hole for brakes on the rear of the frame is drilled at an improper angle. Don't know if it's a defect on my bike or if they're all like that, but it would need to be welded up and then re-drilled at a different angle. Or you could try messing around with the u-brakes to give them a sort of angle.
I find a cheap set of front handbrakes works great. The more expensive ones tend to lock the wheel and you go face-first into the pavement. Do some road testing when you get them at slower speeds (and with a helmet).
Other than that, at least get a new hub for the rear wheel. THIS
is what happens after ~100 miles to the stock one (says "FALCON" across the brake bar). Some are chrome and some are black. The one in the picture is chrome, but I had the black one and it did exactly the same thing. New hubs are like $30, and I believe the Shimano CB-110 (sometimes called the CBE-110 or CB-110E) will fit the same spoke set (260mm & 258mm). It's also pretty in-expensive and still gives you the coaster brake.
The expression of time one
enjoys riding a Happy Time motorized vehicle. 2:
A high-risk situation one participates in with a Happy Time motorized vehicle that society considers to be reckless, dangerous, and/or stupid. SEE Suicide.