'70 rear bumper question & pics of truck

[69Tom]

I picked up my truck on Sat and drove it home over the weekend. I received a bumper that apparently was originally on the truck.

Does anyone know if this is a GM bumper? It doesn't look like the step up bumpers in the '70 brochure. Basically, I don't plan on putting it back on the truck, so I either sell it or scrap it. If it's worth selling, I might have it blasted then powder coated. Any thoughts on this?

Oh, and here's a couple lousy pics of my truck. I was originally purchased by the University of California and used on campus or for its agricultural program. I believe I am its 4th owner. 307, 4-speed. Very base model. HD suspension is one of the few options.