Here's a couple of pics of the pull-pull setup on my Bristol. It has pull-pull on rudder, elevator, and aileron, just as the full-scale did.
Rudder and aileron was easiest, the elevator uses a single servo with a linkage to a "crossbar" that pivots horizontally, dual horns on the crossbar go to four wires to the elevator halves (one each, top and bottom). Maybe more complex than needed, but works great. I did it this way as sort of 'proof of concept' for later, larger models so I could put servos in places not conducive to running all those wires, and drive the pull-pull setup from a distance.