--- In STMFC@..., Tim O'Connor <timboconnor@...> wrote:
Evergreen doesn't make sheet in black... they BUY black sheet, cut it to smaller sizes, package it, and re-sell it. They could do the same with gray, if gray extruded sheets were available, but I don't think they are. The could make their strips and shapes from the black sheet, but I'm not sure that working with black would be any easier than working with white, and would be difficult to paint.
I'll second the motion for Z section, but in sizes smaller than 1/16", which seems to be their smallest size for angles and channels, too. Actually, it's .060", which scales out to 5-1/4" in HO scale. That's only good for the middle end posts on some boxcars. Most car framing was either 3" or 3-1/2" (can't find a reference quickly), .040" would work well for the later. .030" and .040" would be useful sizes for angles and channels, too.
"Hat section" is problematic, as there was no standard. Many cars, many different dimensions, some that tapered along their length. Since hat section posts were pressings, many from our period also had differing width flanges to make integral gussets at the end of the members. Hat section posts for modern cars would be a possibility, but their flanges would have to be thinner that anything Evergreen currently makes, at least for use in HO scale.