Congrats on your 2-ton.
Not sure how long your truck was sitting, but if it still has the original single circuit brake system (which it sounds like it does), I would be very thorough going through the brakes. No fluid in the master could mean damaged/dried seals in wheel cylinders. A stuck cylinder could mean contamination/corrosion. I'd pull every wheel, then pull every wheel cylinder for disassembly & inspection, and then do the same to the master cylinder.
I always like to make sure a vehicle will reliably stop, before I make it go....
