According to our live-in nanny, a leggy, vivacious Haitian, a goujon is a stud. Based on what she's always whispering in my ear, anyway. Extrapolating from that info, and looking at the image of part number J 266 in the catalog again, I'm inferring that a goujonniere is a stud puller. Adjustable, apparently, from 6 to 100mm.
This surprised the heck out of me, but it almost makes my impression of you, your 79 posts, and your obviously FACOM-centric collection since your arrival here on GJ late last year even more bow-worthy. Meaning, the age, volume, diversity, and condition of your FACOM collection is incredible, and your admiration for it as a brand speaks for itself without need for explanation. That you've amassed it from outside of France, and outside of Europe, is even more amazing.