To me it looks like those burnt up resistors are probably dropping resistors for the lower voltage preamp supply. D10 & D9 appear to burnt up a bit too and it would not surprise me if those diodes test open or shorted. D10 & D9 most likely are 15v or 16v zener diodes that connect to R57 & R58 that regulate the, typically, -/+15v preamp voltages. Now did they burn up when IC's went bad down stream and pulled too much current? Those resistors could be 1 watt with a resistance value of 220-1000 ohms, but it is very difficult to say for certain without knowing what the higher voltage is that it is dropping down. Hopefully you may find someone with this amp that is willing to take pictures of the inside of the amp. Still there could be other components damaged in the amp and simply replacing those components might not fully fix the amp. I would read up on light bulb limiters so you can build one if you decide to go about fixing this amp.