here is a detailed analysis of my expert friend performed on a handful of dead and working modules.
tested at 30ºC and 80ºC giving a variance of 1% which is in spec for a precision resistor = not a thermistor.
fell free to discuss and correct my technical translation if required.
symbol / type / value at 30ºC / value at 80ºC / resistor designation
R1 / SMD / 22,1MΩ / 22,2MΩ / parallel for oscillator
R2 / sputtered / 470Ω / 473Ω / serial for oscillator
R3 / sputtered / 439Ω / 441Ω / serial for emitter
R4 / SMD / 1,0MΩ / 1,07MΩ / parallel for lightsensor
Rb / sputtered / 2,22KΩ / 2,23KΩ / serial for base
Rc / sputtered / 75Ω / 75Ω / serial for collector
Rx / sputtered / 88,4KΩ / 89,1KΩ / pull-up -Uz
Ry / sputtered / 86,9KΩ / 87,4KΩ / pull-up +Uz
C1 / SMD / 27pF / not tested / fixed for oscillator
C2 / SMD / 2,7nF / not tested / lightsensor circuit