A big thank you for all the help and "pointers". I'm working through trying to establish how the Townsend of Steanbridge/Painswick area are related to Theyer Townsend of Filkins. It would seem that the name Theyer was carried on by the family and is the strongest hint/nudge that they must somehow be related. My first foray into their world gives me a William Townsend marr. Elizabeth Theyer circa 1723 (no positive ident as to when and where). William has four children between 1724 - 1730 in Painswick (Henry Tyndal, William, Theyer & John).
A quote from British History Online "Paradise Farm, a gabled house of the later 17th century with a classical east front and suitable internal improvements added in the early 18th century when William Townsend lived there." Paradise is smaller than a hamlet and is near to Painswick. Same references mention an estate at Steanbridge, Slad. Perhaps Gloucester Records Office will have some further documents which will untangle the family tree.
As to why Robert Lawrence changed his name to Robert Lawrence Townsend is a question I may have to put to one side for a while. Anyway, I've now somewhere different to (re)-start my researches which hopefully will bear fruit.
So to sum up I've more to work on now than previously. Contacting this forum has made me revisit information I'd discarded and hopefully some connection will be made. It may well be I end up asking for help on the Painswick/Gloucestershire forum but To end on a pun...Hopefully it's no longer "Paradise Lost" but "Theyer Found".