B,
How were the brakes prior? I voted to remove the cab. Hope I'm not getting you in deeper. When brakes are concerned I'd rebuild or buy MC, lines, Shoes,Wheel cylinders and hardware. Brakes aren't the place to mess around with your kid..........kids or anyone else on the road. It will be easier with cab off to replace/repair the majority of the suspension clean and paint if desired. Not trying to get you deeper but don't want to see you regret maybe later wishing you did. Have fun and good luck with whatever you decide.....Save some time for the new addition
Dan