Sony has 2 numbers you can try.
First is the generic off the part ex. 2SC867-?? often marked
C867-??.
Actual Sony numbers are long ex. 1-###-###-##
On a lot of parts it will have a partial number.
A Sams or OEM manual helps.
Sony IS very fussy about subs. Never sub any in the Hoz / HV
semis especially before the 80's.
73 Zeno
LFOD !