Is there such a thing as factory sbp 15" rims??

I have no idea if my duster came factory with these or if some one had them custom made or what but being that they are in such nice condition I would assume they are not almost 40 years old.

my duster is SBP and has 15" out back and 14" up front.

not sure of width dimensions but I know the backs are wide and the fronts are skinny.

the backs I would say are probably about 8" wide and the fronts 4" or 5" wide.

I know the backs have a deep dish to them and for a tire I am running (if I remember correctly) a 275/60/15 with the 3" relocation on my springs.