> transistors not matched very good
The currents are un-matched, by design. 1mA in one side, 2.5mA the other. So there's gonna be >20mV of output DC offset, except the autotransformer (not seen here) will keep it off the speaker.
Whether hFE is 100 or 500 makes little more difference. In fact R112 to R104+R106 marginally reduces the built-in offset, less with high hFE, but in any case insignificant.
Oscillation is not here. Replaced output devices changes compensation, and "fast" (modern) devices may be as bad as slow devices. Someone will know but it sure aint me.