This document does tell us, though, that all the standard texts (Kauffman and Whisker, as well as more recent publications such as Flying Leaves and One-Sheets and the catalog to the recent Lancaster Long Rifle exhibit) are inaccurate when they state that Dickert moved with his family to Lancaster County. His father and mother seem to have remained in Berks County. Dickert's lebenslauf notes that, after emigrating with his parents, he "lived with them a few years in Berks County and in his 16th year came here [Lancaster] to learn the trade of gunsmith." So it sounds like he was sent to Lancaster to apprentice and lived with his master.
I went to the Registrar of Wills in Berks County today and saw the six documents that comprise the estate records of this John Dickert (spelled variously Tickert and Digert in these records). The inventoried items were worth about £14. John Dickert's wife, Mary, gave up the right of administration due to "infirmity" and "great Age" to "the Eldest son or (on his refusal or Neglect) to other persons" that the court shall appoint. That language sounds pretty formulaic. Jacob Dickert (who as the other document makes clear was not the eldest but the only son) refused the task, as you can see above, and others inventoried John Dickert's estate.