Hi Janis, I have done little to nothing on Jaycocks, since having attained my goal of attaching the Poughkeepsie Jaycocks line back to the Hempstead, NY family, which connects to the family at Stratford-Upon-Avon in England. So if you trace your VA Jaycox line back to the Southern Precinct line that used the names David and Isaiah, they were NOT German.
I did not work on the family in Virginia.I worked on Jaycocks in Hempstead, NY, in Orange and Dutchess County, and Jaycox in southern Precinct, Dutchess County. and Westchester County, and accumlated other information on the extended family elsewhere in the process.
The man I call "Isaiah Jaycox the Younger" was born about 1751 and had a brother David born in that same time frame whohad "Tory inclination, went to Canada then settled in Virginia", so if this was your David, he wouldn't have been in Virginia much before 1783, having been born in NY, and then gone to Canada ca the Revolutionary War, and from there to Virginia. (This was a different David, by the way, from "David of Osnabruck, Canada who married Hannah Alguire, who was from the Poughkeepsie Francis Jaycocks line))
So if we are researching the same family, you are wasting your time looking for David in Virginia before the earliest records you have found, and they were not German. They were English, and some of them were Quaker, so a peek at Quaker records of the area might reveal something re Jaycox.Also, I'd keep my eyes open for Meads around the VA Jaycox folks. There are Mead genealogies that infer a connection between the VA and NY Meads, and Isaiah Jaycox the Younger was married to Esther Mead.
Re: Also, the family was German, heavy accent, but coming from Alsace, which about the time was heavy German.
What evidence are you basing this upon re the Virginia Jaycox line?