I believe I just dropped a Unimate into rear coupler box on A unit, and forward end of B unit for close coupling between units. I know I put an MTL on pilot of A, and of course, rear of B. Right now, they're not in front of me, so I can't say which MTL's I used. The cover for the rear A and B units is tough to engage into box. Think I pressed down on it with needle nose pliers, and then applied some Goo as a safe guard.
Joe D