I use pitted ''boiler plate'' occasionally , mostly for fireplace surrounds, and that can be tough to find. At least a passable substitute can be made in a power hammer...........An option not really fesable with angle iron......Maybe some alternatives would be to find some plate , cut it into strips and have it formed in a press break, or textured strip the same.........Allot of work, just depends on how bad you gotta have it.............
I'm sure there is a stash of that stuff somewhere........Like looking for a ''needle in a haystack'' though....good luck!.......mb