I've always used JB Weld.
That carb looks to be in pretty good shape and all the tamper proof plugs are still installed. If it was running really well you may decide to leave it be, but you may want to open it up and have a look. A lot of times I'll find one or more of the tubes that are installed in the airhorn laying loose.
A rebuild kit will run around $20 and you'll need a can of carb cleaner. If you decide to open it up make sure to count the number of turns to seat on the Idle Air Bleed and Lean Stop Screw (holds the Mixture Control Solenoid in place) so they can be re-installed to original settings. There's tons of info on rebuilds here, you just need to search. Like:
http://www.thirdgen.org/techboard/ca...qjet-need.html (In the process of rebuilding Qjet... need some help)
We still won't mind answering any questions though.