Yeah, chops can mean face.. (really jaw but face is included) so off your face = off your chops
: "Chop" has meant jaw for about 500 years; earliest quotation in Oxford English Dict. is 1505. Earliest quot. for "chops," plural, meaning the jaws, the mouth, and the parts around the mouth, is 1589. It is in this sense that we speak of licking one's chops. OED says the plural "is the more usual form in contemptuous or humorous application to men." Representative quot.: "My chops begin to water" (Fielding, 1733).
also
break (or bust) someone's chops 1970s 1 v phr To verbally assault someone; harass: "I love it here. I can work hung over and nobody busts my chops" --National Lampoon / "Well, she turned absolutely livid, and ever since she's been busting my chops" --Lawrence Sanders 2 v phr = BUST one's ASS [i.e., to work or perform to one's utmost; exert oneself mightily]
From _Dictionary of American Slang, Third Edition_ (1995) by R.L. Chapman