It is almost universally documented in books and family trees that the John Lawson who died in 1761 in Richmond, VA was the son of Rowland Lawson (III) and Jean Glasscock. I suspect that this is based on a 1910 WMQ article, p. 237, stating: "John Lawson's will, probated in Richmond County, Feb. 2, 1761, names the following children...John Lawson of Richmond County was probably a son of Rowland Lawson (III)".
Rowland Lawson's will was probated in 1717 and named his wife Jane/Jean and seven children, most of whom were minors: Rowland, Thomas, John, Anthony, Sarah, Joanna, and Elizabeth. This John was supposed to be the John who died in 1761. However, Rowland's wife, Jane Glasscock's will in 1735, named only two living children, Thomas and Joanna Steptoe. Furthermore, Joanna challenged the will in 1740 and the court record noted: "the Complainants says there is but one eight part of the deceased Rowland Lawson Estate due to his widow by his Will, he then having 7 children living which we find he had one of which child named Sarah we find died before the testate and 4 more before any division of his Estate..."
SO, by 1740, five of the seven children of Rowland and Jean were dead, including John. Therefore, he could not be the John Lawson who died in 1761. There is another John Lawson who died intestate before 3 Jan 1737 in Richmond that might be their son (Richmond County, VA, Order Book 10, 1732-1739, p. 491). Edit: Probably not since he wasn't named in Jean's 1735 will.
This is one of those many families that re-used the same names over and over again in the same geographic vicinity. The Lawson family of the Northern Neck of Virginia, mostly Lancaster and Richmond counties, is fairly well documented, but I cannot place this John Lawson (d. 1761) and am looking for the input of others. I will send private messages to the PMs involved in this Lawson line for their input.