The oldest English-language 'teach-yourself' book on making a classical guitar seems to be A. P. Sharpe's 'Make Your Own Classical Guitar'. I believe that Romanillos used this book when making his first guitar, too. For both of these reasons, it's an important link in any genealogy of classical guitar luthiers in the UK. You can find a copy online if you search for it. It's 32 pages long.
A. P. Sharpe's 'Make Your Own Classical Guitar' (1957/63)
by Joss Winn
, on Flickr
In the book, Sharpe credits luthier, Marco Roccia (1905?-1987)
as the source of information for the book and for checking it before publication. Roccia, was born in England, learned lutherie in Italy and Paris, and worked for The Clifford Essex Music Company Limited
between 1927 and 1977. Sharpe was a managing director of Clifford Essex until he died in 1968. Apparently, both John Williams and Julian Bream visited Roccia in his home in Brixton.
Marco Roccia is the earliest name I have right now for a classical guitar luthier in the UK in the 20th century. To go back further, would be to the Panormo family in the late 19th century. No doubt there are still gaps to fill.