What is a Gent's? 9 \ 11 \ 13? ...more ports the better, right? I like the classics really associated with "air raid" much more than the typical fire and tornado stuff you find in The States.
Sterling M-5, Sterling Mechanical Siren Timer, Federal Electric Co. Type B, Federal C3 1/2, Secomak VS1, Federal Type A (Coded & Standard), AF Timer, various other sirens \ controls