Any time the meter pegs after work is done to the circuit board around the final, look for a solder bridge across adjacent foil traces. A bright light and a magnifier help a lot.
If the meter did NOT peg before you cleaned up the soldering, this is almost certainly the cause.
Sure would be nice if you had a way to test the final transistor. Does make it sound as if the fault that made it get hot has damaged it.
If it checks bad, you should also check R163, a ten-ohm 1/4-Watt resistor on the final's input side. You don't have to unsolder it to do this, just place the two probes on each foil pad, and measure its resistance in the circuit. Most any reading under 12 ohms is probably okay.
73