I've run into this a couple of times myself, the "Megaswitches" all seem to be off too far to get them to line up properly. Here's how I "fixed" the issue, as you never want to send the body back and wait longer and typically the switch is always at fault anyway:
1.) Drill out and elongate the screwholes in the switch to line up with holes in body
2.) Stop by hardware store with the mounting screws and pick up nuts/washers to match
3.) Thread the screws through pickup mounting springs, then the drilled out holes then attach with washer/nut and tighten down.
From the couple of misaligned switches I've refitted this way, they're not "off" enough to try to drill/retap a thread into