If you go with the 'a couple of years older' statement in LtH, and back Bush up to 1774, then he would be around 11 years old in 1785. That seems like the window to me.
1799 and 1800 are too complicated to figure out properly I think. He would have been on the Conqueror in 1799 and in 1800 right before he ships on the HMS Renown, he was in Chichester for only 3 weeks.
Re: oh, horatio.
1799 and 1800 are too complicated to figure out properly I think. He would have been on the Conqueror in 1799 and in 1800 right before he ships on the HMS Renown, he was in Chichester for only 3 weeks.