Does the numbers on the underside of ez track correspond to radius measurements? I am trying to find an easy way to tell the difference between 18" and 22" radius curve pieces. I am trying to set a track up around the Christmas tree and 18" isn't big enough.

I just picked up a F3A F3B locomotive set. Both are fully powered units. Can the be coupled together and then run on a track? I am running a a basic DC power layout, not DCC.

I picked up a box of misc EZ track for cheap. It has mismatch curve track. There is a number on the bottom of the track 92124A3-2, A3-1... Can anyone tell me what the numbers mean or how to reference these so that I can tell what different curves I have so that I can buy some more track? Is there another way to tell the difference on the track?