Hi. I am also a defendant of the same line. There is no indication of a Gustavus Kanester in any documents I can find, but there is lots of evidence of a Frederick Kanester also spelled Knesterich in same Viriginia county as John Henry was born. This line continues in Virginia after John Henry leaves for Tennessee.
The Frederick Kanester seems to lead back to a Johannes Knesterich also Knasterig who arrived as a Palantine German immigrant on the ship St Mark in 1741.