Brake questions

After sitting in storage for about 3 years, I stepped on the brake pedal and it went to the floor. The brakes where ok when I put it in storage(at that time the master cylinder was only a few years old. Is there any problems I should look for or was it just air in the system? I am replacing all of the steel lines (the Right Stuff)and will source new rubber lines locally through auto parts, should I also replace wheel cylinders at this time too? Ooops almost forgot 67 Dart GT with 9 inch drums all the way around. When I had the shop change the master cylinder(I know I could have done it myself but I hate bleeding brakes), I was told to never bring the car back to that shop, cause they had a bear of time removing the master cylinder(had to crawl under the dash and remove the rod from the pedal)Then they had a bear of a time bleeding the system, finally a piece of crud popped out and hit one of them in the arm and left a little welt. Also should I replace the prop valve or should I be OK using the old one?