B-16A Amp Head c. 1964 in Silver.  This model includes tremolo which means two extra knobs on the control panel -- Speed and Depth; some knobs are numbered but the numbers don't appear to correspond to the function that is controlled.  Other than tremolo, closely resembles the other B-16 amp heads.  Also no dedicated cab for this one, though it does have the lower half of its backpanel with a metal jackplate on which is stamped a serial number.