According to the '72 catalog, which I believe was the first time the Coliseum was listed, there was a single 18" front-loaded cab with an angled port at the bottom(30"w30"h15"d)that fit the head perfectly; one or two could be used(in Marshall-stack fashion). There was also a 4x12" with the same cab dimensions--similar to the current Model T cab--that would have probably worked for a tighter sound. There was also offered a slightly thinner but taller (24"w34"h26"d) single 18" folded horn/scoop port cab, and also suggested in the catalog was to use one or two of the old classic sized front loaded 2x15" cab(24x40x15)which by then featured an angled port up and down the right side. As far as T-shirts go, check with Rich B.---he was most gracious in helping me get one, but that was some time ago.