The VT-132 is the American designation of the 12K8 frequency changer. The design was as a purpose designed frequency changer. See also6K8 that has a diagram of the special construction.
The local oscillator would produce 7.5 Volts peak to peak signal from the triode section.
The RCA logo.
The octagon with the commercial Type designation.
The thin metal tube envelope is 25 mm in diameter and, excluding the IO base pins, is 62 mm tall.