I sent the note on to a fellow that might be able to help with this
discussion. Here is his reply.  Les Buell

Les,
I regards to the letter you fowarded to me.
    I would tend to disagree that The Plymouth they are taking about is
Plymouth, PA near Wilkes-Barre because at that time Plymouth was not
established and it would have been on the outskirts of the Wyoming
settlement. Not a lot of chance that a soldier would be there during this
time (1777). The Wyoming settlement was
8 months away from the Massacre and would have only had some Militia and that
would have been in FortyFort and Wilkes-Barre proper.
My guess it was somewhere near Plymouth Meeting North  just North of
Philadelphia.
Jim