Just to intervene, I'm afraid probably in an unhelpful way, we in Faversham are interested in a William Saxby who in the 1860s seems to have been the town's first professional photographer. The name isn't a local one, and I seem to recollect that indeed it's most an East Sussex one.
Having said this, a couple of Saxbys worked in the local gunpowder industry in the later C18 and early C19. Maybe the first was poached from the Battle/Sedlescombe factory. You can find a direct address for me if you go to
www.faversham.org and look for the Tourist Information Centre.