OK, I've encouraged myself to scan this catalog (and it's time-consuming so I know why I was dragging my feet), here's my favorite page, these are the classic 500 series hubs, but the "track" variation "520":

I'm going to try to post the whole thing to VeloBase, but would like to be able to name it with the correct date, there's no date on it that I can find, but probably many clues to people who know more about Mavic than me: such as when certain "ATB" units were launched...

If you can ID this catalog's date let me know. Here's another page that might help (ATB long-cage RD), but look for it (complete) on VeloBase, some day soon.