you could sneak it in as a bonus GA, but it should not be actual wagon of a train - because according to event rules maximum level requirement of GAs should be lvl3 ;)

Hey man, you've also missed one of the rules:

• Set Contributor Level no higher than 3

Edit:
I realized that this sounds somewhat condemning so I just wanted to state that I had no such intention :)

Thanks for this sneaky chance :-)

Thanks for the bonus 7+ wagon, Stewart. :)