Bob,
Around the corner from Coin Corner, on Main Street in Oregon City, you will find "Quality Farm Toys and Hobbies". It's a pretty neat store, they have some O gauge but seem to specialize in G gauge. Matter of fact, I think I am overdue for a visit myself. The best train shop in the PNW in my opinion is Eastside Trains in Kirkland, WA. Kirkland is about 3.25 hours by car from Portland.
Chris