Nick - Lots of questions sir, and some are better asked separately from the brakes, like the axle seals as that can keep the focus on a single topic to see you through to success.
An observation from your pics if I may. Your first pic shows what looks like your passenger side rear brake setup, based on the location of the parking brake cable. If that is correct, the parking brake components that connect to the cable and shoes appear to be assembled incorrectly. Below is a diagram showing the 1/2 ton Huck brake setup with the parking brake components. It's from a 1941 Chevy Master Parts Book, but I can confirm that the component parts are the same for 1937-52 1/2 ton (and 3/4 ton) Huck brakes as mentioned in a related conversation
here.
It also appears from that picture that you may be missing some critical parking brake items (eccentric adjusting bolt hardware) for your parking brakes to function correctly.A note before you go further, read through Section 5 of the Truck Shop Manual [this
1941 Shop Manual is the same as other Huck brake information and can provide important guidance on steps to take in your disassembly/reassembly. Give it a thorough read to familiarize yourself.
After that I think I would start by completely disassembling those brakes, lay everything out to see what you have, assess for any missing or unusable pieces and confirm correct side of truck where they belong (the parking brake levers and struts are side specific) and then ask more questions with added pictures.
I think you would be able to handle the brake work without having the Herbrand 188 tool, but it maybe less frustration to acquire one and use for your work. They can be found readily on ebay
Herbrand 188 Huck Brake tool.
Let us know when you have more questions.
