One set of my paternal great-grandparents (surname Dobson) both worked in service at Keele Hall in N Staffs, ancestral home of the Sneyd family (Ralph Sneyd was in residence at the time they worked there - late 19th/early 20th centuries). The Keele Hall estate is now encompassed by the Keele University campus.
I have quite a bit of info on the (Keele) Sneyd family, as a background to my family history interests, although I'm afraid I have no genealogical info which might help you link your line to the "posh" Sneyds! I would be surprised if there WASN'T a link as it's quite an unusual surname and Audley isn't far from Keele.
Have you any further information on Theodosia and Samuel? The Keele University Library has alot of information on the Sneyd family, so it might be worth contacting them to see if they can help:
Keele University Library Helpdesk
Telephone: (01782 58) 3535
Email:
[email protected]
best wishes
Clare