I was given a box of Marx cars and engines and asked to get the engines running and if possible, sort them into the two "original" sets. I am using Eric Matzke two books as reference for ages, however there does not appear to be a section detailing what cars comprised a set.
Set 1 is a 1666 steamer that does not appear to have white stripping (date??) , followed by an AllState tender (date??) . There is an AllState #564 caboose (1959).
Set 2 is a Rock Island #799 70 ton switcher (1959-65) and a Rock Island #17858 caboose (1953-73).
The other cars are:
Pennsy gondola #347100 (1952-73)
B&O box car #467110 (1958-73)
Erie 7 stake pocket stakeless flatcar, no number, no load (?-1973)
City Service CSOX tank car # 2532 (1960-70)
I am speculating that Marx did not have sets as such like Lionel or MTH does, but put into cartons whatever cars were in inventory.