It appears that at some time and for some reason Marx produced a series of six inch cars on eight wheel frames with scale trucks and metal fork couplers. Here is the tank car. I have also seen this same car but with red painted ends and dome. Elsewhere in this site you can find a military car. Greenberg's Guide to Marx Trains Vol. 1 lists a Brown, High Sided Gondola but shows no picture. If you know of any others I would like to hear from you and I would especially like to see pictures.

Courtesy of Al Woodward