Stumbled upon the grand opening of "Thomas Town" at the Six Flags in Largo, MD (just east of DC) today. 2-foot gauge gasoline motor powered, about eight other rides. Looks like normally they will charge for the Thomas ride above and beyond the park entrance fee. It was free today. Started to see ads for this on Cartoon Network a couple of days ago.
The hacked up (re-engined) Porter is hidden on a back siding, only visible if you take the 3-foot train ride. It has been there for a number of years, although looks like it was moved a bit this year, perhaps because of track work. I think I saw this running back in the early 1990's.
High res:
http://www.ladyandtramp.com/photos/d/31786-1/CIMG4639.JPG
Bob