Oddity. 2-6-4, scratch built by somebody, excellent workmanship, unfortunately mounted on an AHM chassis or partial chassis, emulates the esthetics of a PRR Q-1 4-6-4-4, may be 17/64 scale.
Plenty of room for a 4-wheel pilot truck - so why not a 4-6-4?
Very strange cab floor - supported by 2 brake cylinders....? Partly it's the angle of the photo, but this rear view shows how tall the loco is, which made me wonder if the builder was going for 17/64" scale, rather than 16/64 (1/4)" scale. A 4-wheel front truck and a decent 6-driver chassis would make this a striking piece.