So I've taken the rear wheels off plenty of bikes before, but this is a first.

1985 Raleigh Sportif. Loosened the back wheel to remove it for a tire change. Aaaaand off comes the RD! I had never seen a "claw" derailleur before, so that was a surprise.

Anyway, I figured I'd do some Googling to figure out how to get it back on correctly, and I found this video showing how to line up the mounting nut in the dropout and line up the claw RD with the dropout:

http://forums.bicycletutor.com/thread-1813.html

... which all makes perfectly good sense, except that as far as I can tell, my derailleur was held on *only* by the same nut and bolt the wheel was mounted with.

So I guess I will just try to figure out how to align it like it was aligned before after I get my tire changed, but is this a scary "oh, holy crap don't ride that bike again until you have the mounting nut/bolt" sort of situation? Naturally, I *just* dropped my other bike off at the LBS with a "no rush, I'm about to go out of town until the start of next year," thinking I'd be riding the Raleigh in the meantime. Thoughts?