Since I'm more interested in the "shortest distance between two points" method rather than all these convoluted steps, I sidestepped them when converting my non-TMCC-R/S equipped F-3s to TMCC-R/S equipped ones. Perhaps not the cheapest method, but certainly easier and quicker, which is worth something if you need to do other things with your time.
I find a Postwar Celebration or other F-3 set at a decent price, which has TMCC and R/S, electrocouplers, directional lighting, cab interior and figures, etc. already installed, and simply swap shells. The only additional step is to transfer the antennas, a simple task. The one procedure that requires a bit of time is mounting the speaker in the B unit. I haven't tried to mount it in the fuel tank, but will take a look at that if I do this again. Rather than that, I made a baffle and mounting system, and mounted the speaker in the roof of the B unit (and in one case, an A unit), with the speaker pointing out the roof vents. The volume control knob I stick out the back door window - just fits.
Lastly, I took the old chassis' and mounted the unused shells on them, and sold them. I have done these conversions to 3 MPC era F-3 sets.
