Steal. As far as fixing the handle, you can remove the entire faceplate by removing the (6) remaining screws and the face will simply pull off. This will allow you to easily access the rear of the handle and replace the screw.
WHILE YOU'RE AT IT . . . take the extra 5 minutes and remove the meters (two screws each to remove the flat bezel retainers), remove the knobs, unscrew the power switch, and unsolder the panel lamp. If the panel lamp is OUT, McIntosh stocks them (part # in the service manual). Once you have the faceplate OFF and stripped of it's goodies, get some car wax and go to town on it. You'll be amazed at how good you can get that thing to look. I typically also repaint the meter bezels while it's all apart too.
Finally, remove and reverse the cooling fans so that they pull air through the chassis and don't blow onto the heat sinks.
OH, and it goes without saying that you'll be doing all of this with the amp unplugged! Sorry . . . I couldn't resist.