As read around the barrel, one gap only between 5 and C
from someone's cherished 1960s Japanese radio. Only a signal one , probably Si in otherwise mixed Si/Ge. Form like 3 pin version of TO105 or TO107 , black dome, brown barrel, slightly "D" plan view. Italic lower case f logo on other similar transistors, Fujitsu logo of that time?
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on