I'm taking a different angle today - I am following up on the idea that the Waltons might be of German descent .... I tried to make a connection with the Byberry Waltons again today, with no luck.
But... this is interesting. I Googled a book containing ship lists and there is a Johan Valltin listed (p. 677) Never before have I considered this spelling, but it might make sense. A German pronunciation of Walton - "Valltin."
The book is Pennsylvania German pioneers: a publication of the original lists of arrivals in the port of Philadelphia from 1727 to 1808, Volume 2 by Strassburger, Ralph Beave and Hinke, William John. Call number at FHL 974.811 W3s 1992.
I am going to look more into it - also, there are two others to try at this link:
Printed sources: a guide to published genealogical records
By Kory Leland Meyerink
http://books.google.com/books?id=z8DP4mmc-QYC&pg=PA516&dq=german+pioneers+pa&hl=en&sa=X&ei=Oo5nT8v8BOmSiQLY_ZjpBg&ved=0CEYQ6AEwAw#v=onepage&q=german%20pioneers%20pa&f=false
I also need to look more into these sources:
The peoples of Pennsylvania: an annotated bibliography of resource materials
By David E. Washburn
http://books.google.com/books?id=O6rnKYe2KKwC&pg=PA86&dq=german+pioneers+pa&hl=en&sa=X&ei=Oo5nT8v8BOmSiQLY_ZjpBg&ved=0CFsQ6AEwBw#v=onepage&q=german%20pioneers%20pa&f=false