Rubber brake line replacement

[Waterloo]

If those air lines are bad, odds are so are those brake chambers. I would go through everything if you plan on driving it, slack adjusters, S cams, etc. No telling on the valves either, they may need to be replaced too, especially if the truck has sat like you said. Oh, and the u joints in the driveline, lot rot will destroy those in short order if they were not heavily greased before parking. Carrier bearing too. Been there, done that.