Tannoy Dual Concentric loudspeakers have been around since the 1940's. Parts are available at places like Speakerex, in Fla. Cathy Satin, the proprieter, is a dyed-in-the-wool Tannoy enthusiast, and a frequent contributor to the Yahoo Tannoy forum.
Hans Hilberink's Tannoy website is a wealth of information on Tannoys.
I couldn't afford new or even used Tannoys in the current Prestige line, so I bought ca. 1975 12" HPD DC drivers, converted them to Hard Edge surrounds, and buit custom cabinets and crossovers. They are the speakers I will die with, no ifs, ands, or buts.
I drive mine with an SET 300B, @9 Wpc, in a large room, to concert level (or nearly so) with great detail, resolution, and musical satisfaction hitherto unknown to me.
Do make an effort to listen to Tannoys, they may be just what you are looking for.