If the head gaskets aren't leaking, I'd leave them alone. Attempting a retorque on an aged engine might result in false torque readings and start leaks.

After you clean up the water pump flange area of the block, hold the pump against the block (without the gasket) to see if it sits flat against the block.... or if it rocks. If it doesn't sit flat, check to see if there are any high spots on the block - if so, try to get it flat before you final install the pump. If you find a twist between the pump flanges, that might be ok because the bolts will pull it flat.

Frank