It would be even easier now, with cheap USB joysticks available. Recently I bought a USB joystick from Curry’s for 9.99 (PC Line is the brand, but looks very like a Saitek Cyborg). Anyway, all you would have to do is take it apart and use one of the potentiometers on the pedals, using an extended cable to connect it back to the joystick’s innards. Plug it in and configure it as your second joystick, and assign the rudder operation to the required axis. Sounds much more complicated than it really is.
You could use the other pots in the same way, to make levers for mixture and prop rpm. I found r/c model pushrods and bellcranks useful for connecting the controls to the potentiometers.

Using this method I built a setup using these pedals, a Hunter throttle and a Canberra control column. Worked great but I didn’t really have the room for it so only the pedals are left!

I put the throttle in the raffle at the DX meet, BlueRobin now has it. Here’s the stick: