Replaced the unmatched, uncomplimentary BD139/MJE253 output transistors with matched and complementary 2SA1930/2SC5171
DC offset never goes above 5mV even at the highest point on the volume pot.
Sound is a lot smoother and resolving, doesn't have the treble sizzle that it did previously. I don't know if that's a good or bad thing, but it doesn't seem to have lost any detail, just a lot smoother sounding.
with 4.7ohm resistors and biased to 25mA the heat is very reasonable too. all good for now =)
thanks for everything Nate!