Jason,
It was called the "Iron Horse" restaurant (if I remember correctly) and sorry to say, is no longer in business. The only other train-associated place I can think of right now in Seattle is "Andy's Diner" on 4th Avenue, just south of the stadium area, on the right (west) side of the street as you are heading south on 4th. Food is not delivered on G-scale trains like at the old "Iron Horse", but the restaurant itself is made up of old passenger coaches, including one marked as being Teddy Roosevelt's personal coach (or something like that). Have fun if you decide to go...reviews below:
[
seattlepi.nwsource.com]
[
www.dinercity.com]
[
archives.seattletimes.nwsource.com]
--Sasquatch