You may already have this, but perhaps others may be interested:
From "The Ambrose Brewer Family1753 - 1855" by James F. Bowman:
..." The Revolutionay War pension record of Isaac Brewer (North Carolina R 1185) gives some important facts about his family as follows:His father was Howell Brewer who was of North Carolina but lived in Wilkes County, Georgia when Isaac was born in 1763, then moved to Bedford County, Virginia when Isaac was 4 or 5; then to Chatham County, North Carolina, where he lived until Isaac was 24 or 25 years of age;George Brewer was a younger brother of Isaac and in 1846 was living in Wayne County, Tennessee;Isaac had an uncle John Brewer: Simon Brewer, Coosa County, Alabana was a brother to Isaac:Howell, the father of Isaac died some place unknown to Isaac but in west Tennessee, with his second wife and second family."(Notice this says 'west' Tennessee)
So, adding up the years in this, Howell would have been in GA in 1763, then to Bedford County VA in 1767-1768, then to Chatham Co, NC. at an unknown date, staying there until about 1787-88.At this point, Howell, Sr. would have been about 65-70.If he's on the Randolph Co., NC census in 1790, then he would have had to go to TN, (either east or west) after that.
(I have this as well:Howel, Sr., Howel, Isaac and Nimrod Brewer signed the Randolph County, NC, Petitions 1785 and 1788 [from USGenWeb Archives] but Howell, Sr. did not sign the 1788 petition)
The Howell Brewer that ended up in Owsley Co., KY is Howell Cobb Brewer, who was born around 1790 in Moore Co., NC and is a grandson of the first Howell.