Anyone have any wiring problems (i.e., heat damage) from welding done under the car?

I was changing my oil yesterday in my "new" 93 240 (had it a month) and noticed that there was a hole punched in the passenger underside metal. It's right under the front passenger's right foot - about 1 foot back from the jack connection pin behind the front passenger wheel. There's a circular plate welded there during manufacturing, with a matching one on the driver's side. Inside the torn hole, you can see a 2 sets of wire looms running along the rail (from the front to back of the wagon) about an inch from the edge of the whole.

There's matched damage on the driver's side, so I assume that some *&%$#@ put the lift arm in the wrong place, and the end of the lift pad tore the hole in the soft metal. Both damages look new, so it was either the local muffler guy who was tack welding a loose heat shield, or a Jiffy Lube tech where I had to have the oil changed (under duress) several states away from home.

Would welding there possibly damage the wire looms? That would be a royal pain if the wires were melted during the welding process. A DIY option is for me to drill a hole in the center of the circular metal piece that was punched upward, pull it back down in place, secure it, glue it with JB Weld, and cover it with undersealant.

I prefer having the local muffler guy weld it (especially if they did it in the first place), but don't want to have melted wire issues.