Sorry, I don't know anybody who's been inside theirs. That said, some poor boffin must have assembled them at the part vendor's factory long ago so I guess it's possible to reassemble all the bits of it.
For anyone who might ever think of taking one of these apart be sure to read the Details (warning) at bottom of that part's DMC parts listing page, shared here:
There's a reason these are stamped "DO NOT OPEN" and that's because it's filled with springs and other tiny little parts that will go a dozen different directions when you open it up to see if you can fix it. Go ahead, try for yourself. These will still be here when you get mad and give up and want to buy this beautiful, original part.
DMC staffers have a good sense of humor and lots of valuable knowledge to share with us.