Oops! I was beginning the "half Razor" mod to my MMGs (see the Asylum for details). In the process of removing the staples I slipped and put a hole in the tweeter foil. I took a shot at a simple repair, first with aluminum foil which wouldn't maintain a good connection, and then a piece of 24awg silver wire and Scotch Magic tape. I cleaned the existing foil trace one half inch in both directions from the hole with nail polish. The silver wire had enough substance to maintain a good connection.
Here's the hole.
Here's the foil.
Here's the taped silver wire.
I put it all back together and so far so good. No rattle or buzz and no difference that I can hear between the two speakers. I'll let you know if it fails.