I have copious amounts of notes on the family ofMatthias. Far too much that could be covered in any email. I would recommend that you view an online version of Orline St. John Alexander's "The St. John Genealogy". This can be accomplished by running a Google search on the book and it should pop up.
The book itself is not perfect in its research, as the author expresses in her forward. However, it is perhaps the most comprehensive work exacted on Matthias' descendants.
You should also be able to extract a fair amount of information from this forum as well.