Carpenter's glue works great for teh jackplate. But here's something else to consider, to wit: three things to add to your gig bag.
1) a 1/2" hollow-shaft nutdriver (most 1/4" jacks mount with a 1/2" nut, as do most volume pots- but check yours to be sure),
2) a selection of spare nuts (2 or 3 in a little teeny ziploc) so that if you do lose one at a gig, you can just replace it, and
3) Loctite.
Every instrument that comes into my posession gets a tiny little dab of Loctite #290 Green wicking threadlocker on its jack nut, and also on the nuts that secure the pots to the pickguard. This magical goop works on parts that are already assembled: it wicks down into the threads and locks them without having to pull the apart. It's one of the finest substances ever for race car prep, so it is only fitting that it have a musical use as well. If you have the nuts off, then use the regular #242 Blue (medium-strength) stuff. But the green stuff wicks right in and locks those threads well enough for rock&roll, and you don't have to pull things apart to do it. Available at finer gearhead emporiums everywhere: every town in the country has a NAPA or something similar.
Caveat: use _very little_, and clean up the excess. Apply only to the threads: don't let it get on the joint between the pot shaft and body, or tone/volume adjustments will get _really_ difficult. But use that stuff, and your hardware is very unlikely to work loose again.
