You have a good start. 1869 & 1872 for naturalization from Pennsylvania. Go
to your library and see if they have the books "Germans to America" and
search to see when they actually left for America. ! would start back in
1860 and go forward and find their names. This will verify when they left
Germany and what ship they were on. Once you know this, go to the Family
History Center of the Church of the Latter Day Saints and get the film of
Germans to America with the ship manifest which will give the name of the
town they are from and where they shipped out from.
Also start looking for census records in Pa. when they got there. Ellis
Island did not open until 1892, so there is no record there. There were many
ports open back then, so you will need the ship manifest. From there you
work both directions, Germany and Port of entry to Pa.
This start will give you plenty to do.
Paul Fletcher