I just got the test boards from the PC fab house. There was 1 surprise, but wasn't hard to figure out. I'm trying to have some to show and sell in Carlyle this weekend.
It mounts in any piece of rolling stock you like. A magnet sensor goes on one of the trucks and the display goes any place you like. The thing is powered by 2 AAA batteries, which should run it in excess of 100 hours.
How far have you gone?