Get him a M923A1 like yours! Or give him yours and get another one yourself! These are such neat trucks, I love everything about them for what they are, not what they aren't, and fully intend on getting myself one, possibly even as a first vehicle (18 y/o college student here) and daily driving it, wherever it will physically fit! My roommate bought one as a 14 year old, no joke, and daily drove an M35A2 for awhile in high school! We actually met through Steel Soldiers when I posted something on the recovery/mod thread about it, also a M923A1. Turned out we were so similar it was scary, same birthday, from the same places, etc. Still has it now, 6 years later. I'd love to go "meet" that truck someday, it kind of indirectly shaped a whole chapter of my life, in kind of a weird way. I've been told if I come visit him back home I can come drive it.
Agreed, though, start him young! He'll grow up loving these trucks, too.