Mossberg as in the same company that makes shotguns. They briefly made bicycles in the early 70s.
And having thought about it for a while, the frame was heavy steel and STIFF. I gave it to my sister, it had Suntour stuff on it.
The cheap Campy stuff was on a Peugeot bicycle I picked up for $50 a couple years later(I was still in HS) and I rode the crap out of it. Trued the wheels, new tires, cables, and handlebar tape. Looked brandy-new and worked like new when I was done.