From the squeak license...

   "You may distribute and sublicense such Modified Software only under the terms
   of ___a valid, binding license___ that makes no representations or warranties on
   behalf of Apple, and is no less protective of Apple and Apple's rights than
   this License. "

That seems like the key phrase but It seems to be a large majority of the code base
now does not belong to apple, but what license is it?  My suggestion
is to clarify what the new contributed software has been/will be licensed
under and leave the historical Apple license alone perhaps with a note that
the fonts in question have been removed. Make the curent squeak-l license
apply to a small a corner of squeak as we can. (I'm not sure exactly how the
"Exhibit A" clause should be interpreted, as my brain stack faults
when I think about it. I see it the way out is that it's highly unlikely
that distributeing software patches independent of apple's origional code
and containing no part of apple's code is a "sublicence")

That way we minimise the risk of noisily opening Pandora's worm can and waking
a sleepy dog.