Here's some examples from my collection of household combination tools. It look's like skylab's is similar but slightly different than the second down on the left.
Top left is marked "Pat. Aug. 24, 1875", bottom three on the right are marked "Pat. 1902, 1903. Made in USA" and one on top right is marked "Pat. 09". Rest are not marked. All the ones on the left have a small glass cutting wheel on the ends.
Skylab, Are you sure there isn't a small glass cutter on the end opposite the can opener? Looks like something is there.