Circa 1915 - this orange / red color variation appears to be a tweener? Early body on a later frame! The frame was never embossed, the older hook style couplers are riveted to the frame.

 Probably the most common of the numerous variations, different from the early pre-1915 version in that it has white litho slates.

Similar to car above except the red litho is much darker almost maroon in color. This darker red litho is also used on the 56 caboose and usually shows up on late equipment 1928-30, but would not rule out earlier production also. 

Almost gray with a pinkish tint, this appears to be the variation pictured in the 1930 catalog, but don't know if we can date it to that time period specifically.

White with green slates - another variation almost impossible to date. 

Circa 1915 - Extremely rare - deep green with white slates and black wood grains.

Circa 1916 - This one is also green, white and black, but the wood grain is lithographed into the entire car

Circa 1930 - Probably the rarest of the group on this page, this painted version is from 1930. It is maroon with silver lettering the number is rubber stamped on each end. A similar 6" car exists and There is also a matching No. 56 caboose that is also painted and rubber stamped.  Also see similar 6" No. 63 gravel