1st Series - 1921 or 1922 1 gauge bodies, couplers
2nd Series - 1922 - 1925 early truck without journals
3rd Series - 1926 until end of production, some freight cars continued
with the original IVES bodies right up until 1930 and would be found with
snake pull couplers starting in 1928. Others changed over to American Flyer
and/or Lionel bodies starting in 1928 and would be considered Transition
cars.