1446 should work ok, rm used both types of transistor in the 2 transistor kl351p and the 4 transistor kl500,
you must change 2 transistors, do not mix transistor types,
you have 2 x 68ohm resistors missing, they help make the amplifier more stable and help with impedance matching,
you should add them where you see the blue resistors in my pic, without them sd1446 may become unstable,
that is a filter board added because of damage to the circuit in that area caused by a local stations bad soldering,
good luck.