Is this seriously not a RPG bumper? The owner is a member here and said he had two of them. He's got other parts on his truck from RPG and RPG even commented on his truck in his posts.
From what I understand, It seems like RPG commissioned a set of front and rear bumpers to be built in Taiwan, obviously to cut costs. When they got whatever batch order of these Taiwanese bumpers, they weren't satisfied with the quality / construction of the bumpers, so they decided not to sell them to consumers under the RPG brand. Using good business sense, they probably tried to recoup their investment in the failed Taiwanese bumpers and sold them for cheap to a third party who is selling them now.
I'm guessing the welds are not as pretty or well done, but it's the same basic design.