I have posted some images of the variations on the 2200 series
boxcars.
2202: Small and Large lettering. Also, the small letter version has
very flat paint, while the large letter version has a glossy paint.
Also, variations on the insert. Large says "2202 Pennsylv. Box
Car", while the small version's insert is "2202 PRR 41' Box Car".
2201: I found three variations. Top version has different slant to
the Speedway lettering. Lettering is a little thicker on this
version. Insert says "2001 F. E. C. 41' Box Car".
The second version has the flatest paint. Top and bottom version
appear to have a satin paint that is turning to flat, while this
version appears to have had a flat paint from the beginning. Also
this version has the darkest blue. Lettering on this version is
faint. Insert says "2201 Florida East Coast Box Cars".
The third version has the same lettering pattern as the second, put
the lettering is darker. Glossier type paint, similar to first
version. The insert says "2201 Fl. East Coast Box Car".
2204: Top version has a slightly more organge color to the top
paint. Also, lettering not as sharp. Great Northern is thicker.
Look at the differences in the G.N. above the number. Top version
has flatter paint. Insert on top car says "2204 Great Northern Box
Cars", while the bottom insert says "2204 Great Northern 41' Box
Car".
Have also posted a photo of the 2286 variations, will provide more
information later. Ross.