I believe you are probably right about your David being the son of Abraham. But I think your David was probably born in Ohio instead of Virginia. Because Abraham married Sarah Richards Aug 24, 1815 in Champaign Co., Ohio, then married Elizabeth Newcom Mar 2, 1820 same Co. So I think your David would have been born in Ohio.
My David (also son of Rev War Christopher John Oppy) bought a land patent in Champaign Co, probably for his brother Abraham. Go to glorecords.blm.gov to look up
He also bought land in Scioto Co which that part then changed to Adams Co. Christopher Oppy, their brother also bought land in the same county as did my David's father in law Jesse Edwards.
Your Abraham is in the 1830 census in Logan Co., Ohio then he bought a land grant in Grant Co., IN where he died in 1860. I think his children are David, Jacob, Sarah, Melissa.