The hydrovac is usually more in need of rebuild than the master cylinder because most people were afraid to dissemble them. Besides that, in that trucks day, pumping the brakes was one of the skills you learned to do to drive. If your hydrovac is bad, I see you are listed in Texas. San Antonio Brake and clutch rebuilds them. Concerning tires, there is probably nothing wrong with your wheels. Many tire shops refuse to change the old tube type wheels. That is what cages have been built for. Or you can put a chain around them or put the wheel in the rear axle of the vehicle with the stem to toward the vehicle. The most important thing is to have a clip on chuck. Tubless versus tube type is always controversial. To run on a commercial vehicle there is no question that a tubeless radial is superior. However on a classic vehicle, I prefer tube type nylon. I have some 40 year old tube type nylons that look dry rotted, but if you keep them inflated, they just keep running. We are in the trucking business and have about a dozen trailers we took out of service 10 years ago and about half of the tires have blown out just sitting there. The big thing is to stay clear of the lock ring or rings during inflation. I have never known a lock ring to blow off once it is seated. And I have operated over the road trucks since 1964 and my father sold tires from before the war until the mid 70's.