If you elect to sell the Pilot, let me know as I'd be interested.
Not many techs service them anymore, and most have been converted to an Air 1 configuration as the Pilot itself can be a little touchy to tune and parts are scarce.
If you like I'd service your Mk 5, update the yoke if needed, and provide a Balanced Adjustable (R156) or Adjustable (R109) newly serviced in good condition in exchange for the Pilot second stage. The Balanced Adjustable is easier to get serviced as it is basically a metal cased G250.