You might stop by local auto repair shop or auto dealer near you and ask for rep or ask snap on directly is your best bet not sure if they can rebuild being so old thou
Hey neighbor, I work in Bradford! Snap On themselves or Torqueteam are two places I know of. Snap On fixed and calibrated a 1/2 for me for 75 bucks, try them first.
Snap On. They have a fixed repair and calibration cost for torque wrenches. See if you can find a local dealer that will send it in for you. If its only part of the ratchet that's broken he might be able to fix it on the truck.