I don't know if any of the following opens doors, but perhaps the Knortzer/Upp and Sprinkle families were associated if not related:
The Knortzer (Knertzer) family resided in the Manchester communities, as did the Upp and Sprenkle families. (source: The Pennsylvania Original Land Records for York County (Manchester townships)
3--Sprenckle,Maria Elizabethbaptz. 3-9-1760b.Manchester Twn d.>1823 s-Upp,Jacobm.York Co PA c1778 b.York Co PA 1751 moved to Louisville KY 4--Upp,Johnb.1781 4--Upp,Jacob jr. 4--Upp,Elizabeth s-Cunningham 4--Upp,Catherine s-Roberts, G. H. judge (source: http://www.geocities.com/charlescuy/sprenkel.htmlhttp://www.geocities.com/charlescuy/sprenkel.html)
Knertzer and Upp listed in Will: Jacob UPP - will was probated April 18, 1767 by the following: Peter BENTZ of Dover Twp - Tavern Keeper, Philip BENTZ of York - Town Yeoman, and Michael HAHN of York - Blacksmith.
One Jacob Upp is connected to Knertzer (Balthasar Knortzer).(note Balthasar Knortzer family listed in will)
Jacob UPP's will was written May 19, 1758. Executors of the will were sons Jacob and Peter UPP-------- see also ---- Do you know which Jacob Upp is in Isacc Knight Indian Capture lists: John and Jacob Upp's capture?