"The first GP32 had just a TFT (no light) and if you were lucky you found one that reached 133mhz."
If it was less than 133Mhz, it was faulty. It was the same before as it is now; at least 2/3 of everyone's GP32s could over-clock to varying degrees.
The difference nowadays is that it's almost unheard of for somebody to not be able to overclock, and some overclock very high (>180Mhz)