See that "09" in the fourth picture? Flip that picture upside down and it will read "60".
Here's a picture of the Dana 60 I got from a '71 - '72 3/4 ton 2wd w/ rear leaf springs:

Yours looks exactly like mine. I'm betting it wasn't a one-ton but a 3/4 ton truck you pulled it from. Do a quick Google search and you'll see that the HO72 looks nothing like what you've got.
P.S. the numbers you really want for exact identification of a Dana are on the axle tubes. There are a few web sites out there that will help you interpret the BOM (bill of material) number.