KrisBlueNZ
Sadly passed away in 2015
Yes you should replace the eight transistors in the power amplifier section, then run it for a while and see how hot everything gets. If those eight transistors are still getting hot, we can measure some more voltages to see whether they are running at the right current or not.
How are you dealing with the different pin arrangements of the new transistors? You haven't asked about any of them yet. Those replacements, and the replacements for the phono section (if we decide that they should be replaced), have different pin arrangements so you'll have to cross wires over and use a piece of insulation on at least one wire to stop them from shorting together.
You can get data on your replacement transistors from digikey.com or nteinc.com. See if you can work out how to fit the replacements in there. If you want, remove the old ones and take a photo of the top side, and either mark the new part connections on the photo, or I can do that.
How are you dealing with the different pin arrangements of the new transistors? You haven't asked about any of them yet. Those replacements, and the replacements for the phono section (if we decide that they should be replaced), have different pin arrangements so you'll have to cross wires over and use a piece of insulation on at least one wire to stop them from shorting together.
You can get data on your replacement transistors from digikey.com or nteinc.com. See if you can work out how to fit the replacements in there. If you want, remove the old ones and take a photo of the top side, and either mark the new part connections on the photo, or I can do that.