Absolutely spot-on re: Brook guitars, Fred. I owned a Brook Lamorna for several years, until last year. The guitar itself was wonderful, but the super-slim neck got too much for my arthritic old hands, and I traded it for a McNally OM-32 (Irish builder, formerly with George Lowden and Atkin).
So my vote for 'underappreciated luthiers' goes to CiarĂ¡n McNally, in Northern Ireland.