It takes many years, in my case near 50, to develop an eye for restorations vs. original. You not only have to be able to recognize the right color, but also the patina. Very early Lionel was spray-painted, sometimes unevenly, colors were mostly dark greens, maroon and olive. Classic period (started early-mid 1920's) was mostly dip-painted, earthy-tone colors, resulting in paint runs and thick blobs, mainly at frame ends, when the piece was hung to dry. In 1935 colors changed from earthy tones like terra cotta, mojave, pea green etc, to more-primary colors, 45N green, bright red, silver, ivory-white. Also, in 1935, Lionel went back to spray-painting, resulting in a finish with "orange peel" texture instead of runs. Silver is an exception as it was used before 1935, and I don't think it was ever used for dip-painting. Also black frames continued to be dip painted into later prewar production, well past 1935.
A good example to demonstrate would be to look at a 1934-production apple green 653 hopper, next to a 1935 or later Girard green 653 or 2653 hopper. At first, they look the same color, but the apple green 653 has a yellow warm tint, where the Girard green 653 has a brighter-cooler tone. Also you will notice the patina difference, thick runs on apple green, orange-peel on the Girard green one. Trim also helps ID years and colors, as in 1935 Lionel changed trim from brass to nickel and aluminum. In 1940 they would make another big change to semi-gloss finish on a new pallet of colors with mostly black trim and stamped lettering. Both 1935 and 1940 had some transition production which combines colors and trims. Some transition combinations defy explanation, other than "they were just making toys, and they used the parts available on any given day." Don't know if this will confuse or help.
