Ha, my buddy did the same thing and his glue blob slowly slid down near the contact pad after a summer of sweaty sessions. He said the glue stayed soft and collected dust until it stopped registering right clicks completely. Yours might hold longer since you only play weekends, but keep an eye on it when the room gets warm.

Held 380F for about 40 seconds is basically the same recipe I've used on old radio trays, and they're still flying years later. A heat gun with a thermocouple taped next to the work is honestly more controlled than half the guys I know who just wave a torch around and hope for the best. The trick is keeping the heat moving so you don't cook the plastic housing, and it sounds like you already know that.

15 feet off?? That is wild, how does a locate miss by that much on a marked run. Paint can be off a foot or two but 15 feet means somebody flagged the wrong line or the tone jumped to a different pipe. I would not trust those marks for anything after that, every pass would get a test hole or at least a probe before the bucket goes in. You did the right thing stopping the cut, a gas line in a pond berm is a nightmare if it lets go, you get gas bubbling up through the water and nobody knows where its coming from. Two hours of hand digging beats explaining a rupture to the utility and whoever owns that pond.