Reply to "The best gauge of wire to use ?"

If you have an old lighted caboose why not cut the top off and secure a voltmeter to it. Just connect the voltmeter to the wires that were on the light, then you can check the voltage under actual operating conditions. If you  use 14 gage for track,and18 gage for accessories you won't go wrong. I don't like to use anything smaller than 18 gage as it is difficult to work with and is a little weak mechanically. Hope this helps.