It sounds like your just getting started in 3 rail. You seem to have a mixed bag of equipment as far as eras. Lionel system may be exclusive but as of now they are going to be the only game in town as far as command systems for 3 rail. MTH is closing their doors and nobody knows the future of DCS. Atlas and 3rd rail produce a few engines a year all based on using TMCC right out of the box. Your MTH stuff if it’s early Proto 1 can be upgraded easily to TMCC. Check out the ERR line of products for conversions. Anything you buy of recent vintage or new will have Legacy already in place. I can’t see gutting it to add DCC.
What you want will work as far as adding DCC. Not sure on the postwar though. You will have a non proprietary system. You can buy products from more than one vendor. What you will have is a layout that doesn’t conform to pretty much most of the 3 rail world. But it’s your RR and if you feel more comfortable using DCC because that’s what your used. Anything is doable.
I have both DCS and TMCC/Legacy. I just can’t imagine a more user friendly setup as far as getting it to work. One wire. That’s it. No worry’s about getting signals through the rails or fancy wiring. If you go withthe ERR upgrades. Plenty of help on how to’s. Right here on the Forum.
