Thanks, I did wonder about that. Or the navy. Facts known (not that I am expecting anyone to do a miracle for me!) - my GGgrandfather, Edward Curtis, was born to Christopher and Martha Curtis at Falmouth Harbour (?naval connection?) in 1806. They then had a son, Christopher, in Battle in 1811. Census, IGI and parish records pretty well substantiate this. IGI has a marriage of a Christopher Curtis and Martha ?Burgady? in Manchester cathedral in 1799 and census records indicate her place of birth as Manchester, so this could be them. Christopher snr is nowhere to be found on any digital records I can locate. Edward and his brother both live in Westbury Leigh/Dilton Marsh in Wiltshire, both are Strict Baptists attached to the Providence Chapel, Penknap. There are indeed other Curtis' around but none are listed anywhere as related, so far as I can ascertain.
The shoemaking connection was a guess, as Edward certainly passed the trade on to his sons so long as the local trade lasted. He was literate, which strengthens the Baptist connection, perhaps. The chapel certainly attracted preachers from all around the country (who would also have had other trades) so whilst speculating, I have this image of fiery Baptist preachers banging out leather shoes whilst quoting the Old Testament...