Very interesting discussion.
One interesting note, Pete mentioned Overbaugh moved premises to from 267 Boradway to 300 Broadway during his NY stay. That would have put him literally next door to SD&G who occupied 302 and 304 Broadway during this period. Not a stretch to figure how he might have tapped SD&G's existing gun making connections in Prussia.
Ken,
Just to document the source: New York History By Alexander Clarence Flick, New York State Historical Association, New York State Historical Association Meeting
On page 216
"Overbaugh, C.E, New York City 1880's
At 300 Broadway. A specialist in remodeling Sharps breechloading target rifles, and a fine workman."Almost didn't post it because I thought it too trivial.

Pete