Hi Tim,

I am need to working on wiring but I find it more helpful understanding how to wire up a layout when Iorder a few books about wireing layouts off of amazon and there are some dvds that will go into more detals about layouts and wiring as well.  I am a guy that just runs only lionel trains.  I do have legacy and use that on legacy engines and also tmcc engines.  I didn't get to the point of hooking up access. Yet or the switches to legacy yet.  But i stay away from mth because there new trains won't rum with legacy. You would need to buy dcs system as well if you want to run both lionel and mth.  The legacy sytem hooks up to your track with one wire for the ground.  You can hook that to the track of the tracks that your runing legacy trains on.  Also I have a few post war and pre war trains.  I find they run great with a type Z 250 watt transformer its from the earley 30s but you can still find them. Around.  Lionel does sell some smaller.  Transformer but I find troble running some older engines bc the enginess would need more power. And the small transformer have problms running postwar fms and gg -1 but some engines will work but you could always buy the new ZW.but then you be paying a lot more for that when an older visson of the transformer will give you a lot power with four knobs for you can use for four tracks or two for lights and asseory power and the legacy. Tracks you can run more then one train with one koble because the trains reads.how fast to go from the legacy base but have a couple track loops for post war. And engines that don't have computer. Chips in it for you can use the knob to control the speed and also just gets some books about wiring and dvd about to make layouts they show you a lot of info on how to do a lot to your layout and how to hookeverything you want up.

I hope that's helps,

-Rob