The William Scott I'm looking at was apparently born 1764 and died in Scottsboro in 1823. I've got all this info from Canadian contact Barb Pillar on firstname.lastname@example.org
. The only Robert she mentions was William's son (from his first marriage to Elizabeth Rosborough) who died in 1793. He was a Lieutenant in the 59th Foot and was drowned in the wreck of the Sea Horse. Lots of further info online, apparently. As you surmise, I'm interested in Richard Scott who was son of William and Cate Pooler, William's cousin. Richard married Catherine Green in 1854 but we think (but by no means sure) he had a liaison beforehand (with Mary Moffatt) which produced William Scott in 1835 (in Fermanagh) who then married my wife's ancestor Grace Ross in 1855 in Scotland.
Sorry about any delay in sending this stuff. I hope it might be useful.