It looks like an Alpenlite frame, but not the bag. Look closely at the outside of the frame and you can see holes in it where the bag should be attached, and it looks like the area around the holes are discolored from a bag that was once mounted there.
I do question the weight (36-38 ounces on a bathroom scale). I had checked a couple out in the early 70's and they weighed the same as my Kelty with the upgraded hip belt, around 54 ounces depending on the size.
Another problem with the alpenite is the belt frame, which must be closely matched to the size of your hips (the aluminum frame section isn't adjustable). When I tried them in, they were all too big for my hips... So I passed and kept what I had.