Greetings Sir,
There is a paragraph or three about a Henderson Bishop of Charles Town/Charlestown, Jefferson County in "Gunsmiths of PEN-MAR-VA 1790-1840" by William S. Bowers. He passed at age 67 in 1873. His will bequests his "tools and working materials" to his son John and if John carries on the business he was to get the use of the shop free of rent.
Kevin