I don't think I have what you are looking for but I do have an interesting connection between the Barto and Yoder lines in Berks, Co., PA. The reference lists a Barto marrying a Yoder as follows "Isaac Bertho/Barto b. 1786, died in Berks County, PA (per will), married Esther Yoder". I am not sure how helpful this will be to you, but I can send you the document in Word or Adobe Acrobat form if you give me your e-mail address. The document also lists the author/researcher's name and e-mail address so if you contact her, she may be able to help you with your study or it may lead to some other connections that are helpful.