It could well be a cream Tolex/maroon grille Bassman from the 1961-1964 era. Providing it was a 'matched' piggy-back unit, despite the cabinet size it would have been fitted with a pair of 12" speakers, probably Jensen. However, in the early sixties, Leo sometimes swapped & changed between Jensen, Oxford and JBL drivers for a variety of reasons, prior to returning to Jensen (and JBL) once they agreed to build speakers to Leo's specs.
In typical Leo-think, one size of piggy-back speaker cab was able to accommodate various configurations of speakers for the Bassman, Bandmaster (Tremolux?) and Showman models. Only the special order Dual Showman that was available 1961-'62 had 2 15" JBL's. That one must have weighed a bit!
Stephen.