As a newcomer to this forum, I don't know if this has been covered here, but I recently experienced excellent service from Magnepan in rebuilding my IIIA panels. The voice coil wire had become delaminated from the membrane, so I called Magnepan and spoke to Linda. To make a longer story short, Magnepan rebuilt my pair including all new tweeter ribbons and panels for less than $1000 shipped! After some break-in time, they sound so much better than I remember them as original. I am absolutely pleased with this whole experience; I can't think of any other company (well, maybe McIntosh) which offers such excellent support or service for a product over 25 years old, and at an entirely reasonable cost, too. To any other Maggie owners out there experiencing any problems with your speakers, no matter how old, I highly recommend the factory rebuild offered.
Sign me a Magnepan customer for life, (and can't wait to hear where they go from the 3.7 onward),
Tom