I know that if you are really into collecting trains, touching the piece is too much for some, and they are left un-operated in the boxes, never having travelled our 3-rail empires. But if you are willing to operate them, and would like them to operate with little interruption, my experience that some easily reversible alterations can be helpful. First of all, when I get passenger cars with the electromagnetic couplers and slider shoes, I almost always get unexpected and unwanted uncoupling on Gargraves switches, and on Ross, I have similar unhappiness. So I have come to automatically remove the slider shoes, and sacrafice uncoupling, which is a small price because I dont’t generally switch consists on my passenger trains. I do have the same problems on the freightcars with the coil couplers, and I haven’t figured that out yet; I have few, and I usually treat them as a unit with a more modern car so i shift them together; I never have a train made up of cars with coil couplers all in a series.
With regard to duplicating the operating rails that are part of the remote control sections like a #6019, I have found that if I rewire the ground on the operating car by connecting it to the metal car body or operating mechanism, I only need to install one opertaring rail in my gargraves track, which for me is always a tricky task (getting the height right and the proper rail placement). I just tried this with my 1952 (year, not model number!) mil car, and it seems to work fine. I detached one of the two solenoid leads from the slider shoo and loosened a screw at the top of the mechanism. I secured the bare end of the wire there, and connected a push button on my panel board to the operating rail I installed, and voila! the milk guy pushed out the cans!
I believe these changes I made can be easily reversed if I ever want to sell, but I expect to leave that task to my heirs and assignees!