Had to replace a few on my friend's '39. I bent them myself using off-the-shelf brake tubing, a tubing bender, and a double flaring tool for the ends. The biggest problem was the rear brake hose, which I could not find anywhere. Ended up using a front brake hose, and mounted it to the frame using a front hose bracket and clip. Worked fine.
I would recommend you use silicone brake fluid if you are rebuilding the brakes. My buddy paid somebody $1800.00 (!) for the first brake job he had done on his truck, which lasted the typical five years or so, I volunteered to do the second brake job after the truck had sat for about ten years with no brakes, and it is not much fun hoisting those 100 pound rear drums around. Some people will tell you that silicone fluid leaks and will give you a spongy pedal, but I've found that as long as I have good tight connections at all points, and bleed the system properly, I have no problems with it. Your results may vary, as they say. Your brake job should then last you a decade or more, and as these trucks tend to spend a lot of time sitting, that's a very good thing!
The truck is a blast to drive, with the crash box and all. Just don't expect to climb any significant hills at more than about 15 MPH in second! Enjoy it, and it's too bad we've got about 2000 miles between us, or I'd drive it over and take you for a spin.