Depending on how much you want to save, the Magico tweeter is probably this one:
Scanspeak Illuminator D3004/6640-00
You should remove it first to ensure the back looks correct. Magico allegedly has it covered with graphene, but I have no idea if that is true.
From Madisound, this tweeter is about $450, but call or e-mail them to see if they have replacement diaphragms. They’re a little
harder to install, but a lot cheaper than the entire unit. You can take
the original one one out and examine the back, make sure it's the same.