Here are some pics of the throttle quadrant out of my P51B simpit. Originally I had this working with a stripped down cheap Thrustmaster USB stick (the circuit board is in the small box), I am going to change this and hook the pots into a Beta Inovations Plasma USB control unit that I have bought.
From the pics you can see that the unit is basically two pieces of sheet metal joined together with spaces made from mdf board. The trick to making this is to have all the pieces cut out and then mark out one piece and overlay it on the over and drill all holes through all pieces, this will make sure everything is aligned.
regards
chuckcrc