If you are still searching,,,I have a little info. I show James Lockhart jr (son of James and Rebecca) as born 1751 and moved to NS with parents in 1761. They were called New England Planters and were given land grants after the acadians were expelled. James jr brothers and sisters were : John, David, Alexander ( my line), Daniel, Grace, Miriam, Sarah, Mary & Rebecca. James jr married Miriam Margery Knowlton and had 9 children.
**Most of this info from Doug Eagles"lockhart families of NS and NB and other research.** I have more info..let me know if I can be of help