Petter Paul and Mary Ann Ritter.
I have a book the Longriffles of Pennsylvania. By Russell Harriger. About the gun makers in Jefferson, Clarion and Elk counties. It is in out of print but can be found by searching the internet if you want a copy.
This book has 2 pages about Petter Paul and Mary Ann Ritter.
I can email the pages to anyone who would like them.
My second cousin twice removed wrote the book.
Jewl A Wall