Salut JéJé,
I sent my father's beat up 7009 from 1977 to Odyssey for complete movement overhaul a couple years ago. No case work, just movement service. Came back running perfectly. Cost back then: 85CAD plus shipping.
I suspect they have junior and senior people over there; if you're lucky, you'll get a senior watchmaker with more experience.
Since you're in Montréal, I would at least call l'horlogerie Franco-Suisse at 98 Ste-Catherine Est first -- (514) 393-8999; although they mostly service swiss stuff, they likely will take any mechanical.
Good luck,
-xiv