Why is the following simulation not working?
The input impedance of the power-amp is no more than 500 ohms due to the 1k resistors biasing the final output transistors. The input impedance could be a little less given that the power o/p transistors will also draw current through their respective bases in order to drive the 60R load.

The gain of the stage that drives the PA is largely determined by the 6k8 (or is it 8k8) in the drain of Q2 - this gain is being dramatically killed by the PA's input impedance - probably by a factor of at least 6.8/0.5 = 13.6.

This is why your 10V signal is now in the milli-volt region - you need an emitter follower buffer amp - that's what I'd try anyway.