What a haul! Many thanks for all this info, I really do think you are a star sleuth! Will follow these up when I can, so many interesting leads. Much more interesting than packing parcels and writing cards ...
Fancy John Toovey's name being mispelled in John Bate's will - I wonder if his and Hannah's son James Tovey is really the John Bate Toovey you have found? (Oh no he can't be, the will is dated 1796 and John Bate Toovey was born in 1799.)
Again, if it's OK with you I will put what you have found on ancestry and see if it throws up any links?
The London Bate brothers - I did do some digging in the trade directories at the Westminster Archive, and found three entries for someone called William Bate - one in Holden's Triennial 1805-06, a 'taylor and salesman' of 2 Monmouth Street, St Giles; and two in Holden's 1811 - a 'salesman' in 2 Monmouth Street, again, and a 'painter in enamels to Her Royal Highness Princess Elizabeth' of 52 Margaret Street, Cavendish Square: neither of these sounds much like an Officer of Excise! And I couldn't find a Michael Bate at all.
The possible baptism at St Peter's Wolverhampton in 1728 - the font at St Peter's dates back to about 1480, must have a look next time! ( I do need to spend more time in Wolverhampton ...)
Fran