Here is some additional information that may help establish the connection between Isaac Depoy in Rockingham Co. and John Deboy in Monroe Co.
I believe Isaac married Anna Maria Hauer. (Info from Hauer/Howard family.) The name "Hauer" transformed into "Hower/Howard" in Virginia.Anna Maria's brother Christopher Hower/Howard was in Rockingham County in the 1780's and married 2nd the widow Catherine Alstott.(Catherine's first husband, Nicholas Alstott, moved from Berks County, Pennsylvania to Rockingham County, Virginia, in the 1780s, right after the Revolutionary War.) Catherine Alstott's daughter, Mary Alstott (b. abt 1772), married Isaac Deboy's son John.Christopher Howard's daughter (by his first wife),Eva Catherina Howard, married Stopel (??) Depoe 1785 Rockingham County.(Catherine is buried in the Old Bethel United Brethren Church Cemetery as Catherina or Eva Catherina Depoy.) Christopher's son by his first marriage, Jacob Howard, married Sarah Sellers in Rockingham County in 1792.Jacob and Sarah Howard moved to Monroe Co., [W]VA before 1800 and were on the census there through 1850.In 1800 John Deboy and his wife Elizabeth transferred land to Jacob Howard for a dollar.This land was next to the Deboy homestead in Monroe Co.
I have too much information about the Hauer/Howard family to post, but here are a few bits:
"Circuit Court of Rockingham County Court House, Harrisonburg, VA 22801" Jacob HOWARD/Sarah SELLERS, 1792 Catherine HOWARD/Stopel DEPOE, 1785
Old Bethel United Brethren Church Cemetery 010 Depoy Catharina b. 11 Jul 1756 d. 4 Jun 1808 German, illegible name could be Eva Catharine, b. 1756 d. 1808-day & month illegible
MONROE CO.,(W) VIRGINIA ABSTRACTS BY LARRY G SHUCK lists: FEBRUARY 18, 1800 JOHN DEBOY AND WIFE ELIZABETH DEBOY TO JACOB HOWARD, 58 ACRES FOR $1.00 ON NORTH SIDE OF SWOPES KNOB