Hi there folks, old Audionics hand here.
First off, replace all electrolytic caps, both large and small. Electrolytics have a finite lifetime, and modern ones are more compact, more reliable, and quite a lot better sonically. The CC-2 was designed in 1977, after all. We used the best we could get then, but they are horrible by modern standards. Something as basic as Nichicons are far better.
I have mixed feelings about using bridge mode. There’s no free lunch here ... you get twice the voltage, but only half the current. In other words, that 8-ohm speaker now looks like a 4-ohm speaker to each section of the amplifier. Worse, a 4-ohm speaker now looks like a 2-ohm speaker, and I can guarantee you that the CC-2 will not like that one bit. If you want 2 channels with total separation, just use two amps with one half silent (short the input on the unused channels).
If memory serves, there are some blue tantalum caps in the signal path. Those are very undesirable sonically, but in our defense, nothing was published on cap sonics back then. If there’s room, replace them with modern film caps.