Thanks for the further info.I've been collecting Jellicoes trying to sort out my ones in London.I thought William could well have been mine but your info shows he's more than likely not - at least not in a close line.I think originally my lot may have come from the midland area although I've not been able to follow this up yet.
The earliest Jellicoe from my line that I've come across is a Thomas Jellicoe who had children (1) William c 1708, possibly around the St Giles in the Fields area of Mdx and (2) Mary c 1710 who married a Thomas Barker in Staffordshire.I do have a William born 1734 but in London and he was a distiller.
I wonder whether your "two nice Midland kids" came to London because perhaps William was apprenticed to some relative there?just a thought although I've not come across him so far in apprenticeship records.
The names Middleton and Ashdown don't appear in my family I've found so far (Ancestry subscription is a bit beyond my means at the moment).
It seems your William was an upholsterer - at least one of mine was an upholsterer in the London area as well and some were distillers.
Here's some bits I've found in the newspapers, but which you may have already seen.
Mr Jellicoe, upholsterer in Fleet Street to Miss Middleton of Bride Lane (from Lloyds Evening Post & British Chronicle (London) Friday 13 July 1759).Boyd's marriage index says the couple is William and Elizabeth
William Jellico, upholsterer, 88 Fleet Street (from Baldwin's New Complete Guide to all persons who have any trade or concern within the city of London 1770)
Yesterday evening two footpads stopped Mrs Jellicoe of Fleet Street in a post-chaise at the end of Grays Inn Lane, next Pancras and robbed her of money, etc (Morning Chronicle & London Advertiser, Saturday 21 November 1775).This may have been Elizabeth (nee Middleton)
Died yesterday, Mrs Jellico, wife of Mr Jellico, upholsterer in Fleet Street (St James Chronicle or the British Evening Post - London, Saturday 1 April 1780).I wonder whether this was Elizabeth nee Middleton ??