While they are "high bias" Class-A Plinius 102 amps cannot be biased "Pure Class-A to their rated 8ohm wattage output". They run A/B.
To have those heatsinks at a constant safe 55-to 60c they would have to be approximately 4 x that size for the amp to be safe to be pure class-A all the way.
Search all you like and won’t find it stated anywhere they are Biased up Pure Class-A all the way into 8ohms, not even on their archived website.
https://web.archive.org/web/20060115165723/http://www.pliniusaudio.com/pro/pro02.htm
At a guess I would say 50watts of Class-A and the rest is B up to 125w
Cheers George