"Some crisp pix of the internals and the damaged section, transistor type numbers, would help a lot."

Thanks for your help Roly (I am in Warooka,SA) the transistor line-up is different with the last being 2N5680/5682 feeding MJ15003's. I will see how closely your diagram matches what I have and it may give me a clue as to the burned-out resistor and what I can use as substitutes for the other transistors.

Have this wonderful old Amp, probably built in the 70's, to restore. Several transistors blown and a couple of resistors I can't identify. Anybody have or know where I can get a circuit?