I say I must agree with everybody else, this is totally beautiful, the only question I have, cause this is before my time, did they make that tread plate out of anything besides aluminum, I know all I ever seen it in was aluminum, but that doesn't mean there never existed another kind, and what they had back then I have no idea, cause that is a few years before I was born.
Then I wonder if that is aluminum, then did they know to clean it like they do today, it is some kind of acid base, but not that harmful, now you would want to wash it off, butt, it won't eat right through you, they mix it with water at the truck washes now a days, then spray it on, then it turns the aluminum all white looking just as soon as it hits the aluminum, then after they do that then you can buff it to a mirror finish if you got that much ambition, but 99.9 % leave it white like I did.
Maybe somebody else can answer the question about whether or not it was made out of steel to. Cause you would haft to lay an awful lot of rusty things down on it to get it looking that rusty, if it wasn't made out of steel.
Kerry