I was able to make it all work and have the pilot together, now have to reassemble the loco.
I slightly bent the pilot truck to shorten it, have to watch other clearances when you do this.
I re-bent another Irvington coupler, so now it is at the right level and does not let the coupler plunger and spring escape.
I mounted the coupler from underside with the same type screw as the pilot truck is mounted with. I think it is 6-32, has a shoulder and a beveled small head.
I had to modify a fiber washer with a flat side, so it fit up against the back of the pilot.
Some minor bending of the shank for correct height and touch-up with black-oxide blackener and done!
The coil coupler could still be energized, as the power lug is there, if I want to make it operate.