My original tumblr post was here. This image is a cover of Metal Hurlant, containing the text “Tueurs à gages + le garage = 14 pages de Moebius, enfin!” It was first posted on tumblr by brudesworld, where it was identified as the work of Jean-Michel Nicollet (b. 1944). It comes to us via reginaldjuice.
It’s from 1978, issue #29, issued in May…at least according to this French website:
http://bdoubliees.com/metalhurlant/annees/1978.htm