I placed the third row seat from a F@rd Expedition in my 1/2 ton at one point (never mounted it) and it fit perfectly! Great width, great height, everything. Had seatbelts too. Unfortunately I never took any photos.
Tim Sheridan 1947 First Series Chevy 1/2-Ton "Liberty Series" - "Art Deco" - Whatever you'd like to call it. In the Gallery