The "1960 Vintage"'cabinets came with V30s. Maybe he meant "Vintage 1960" cabinets, which could have various speakers, including the G12M blackbacks.
A picture of the cab's grill cloth should tell you which one he really meant. The V30-loaded 1960 Vintage cabs have black grill cloth. The blackback era speakers come in cabs with small check grill cloth, unless the cab is from the UK domestic market, in which case the grill is black... Speakers could have been changed, too... But it's easy if the cab has small check cloth.
EDIT: thumbed through that Dunlop rig rundown vid. Slant with a black grill cloth. Hard to say, but it looks like a model plate was (or at one time was) on the lower left corner of the grill. That would make it too modern to have the blackback G12M speakers. Could have chaned the speakers. Could have painted the small check cloth black. Could have a UK domestic market cab. But I think more likely, it's just a modern 1960 "Vintage" cab with the Marshall-logo V30s.