Greetings Tommy, While I have not personally researched information for you I am the recorder for a LUSK One-Name Study and have a sparse record which might be some help. I have James LUSK 1700- 1763 married to Jennett Elizabeth HAYES b.abt. 1714 - 7 Oct 1770.
They had three children, Sarah, born bef. 1763, John, born bef. 1763 and Robert 1730-1804. I could not find dates for births for Sarah or John but noted that their father died in 1763.
I have a sketchy note from Bob LUSK, a keen researcher now deceased, who indicated that Sarah married "Unknown" REID and that couple had two children James REID and John REID. Could this be the Capt James REID you mention?
Robert, whose dates I do have, married Mary VANCE and had at least 10 children, one of whom was called John b 1769. This could be the uncle and cousin to whom you referred.
With luck you mind receive a reply from someone with more certain information for you. Sorry I couldn't be more helpful.