Nobody will never know.
Sony figures in PSOne age was Production Shipment (that means what they produced and put in the Sony's warehouses before ship to Retail).
PSOne Production Shipment is ~105 million... a bit over that.
But nobody will never knows how much it sold but it is safe to say it sold more than 100 million.
I don't dispute that is sold more than 100 million, as that much is certain. My timeline indicates that Sony announced over 100 million sold by late 2005. My question is whether it could have reached 104 million, or if the 102 million range is more likely. Mind you, even if adjusted down to 102.49 million, it doesn't diminish what the console achieved in the slightest. It was the first console to sell over 100 million units ever. If the Wii doesn't manage to cross 102.5 million units (which is, I whole-heartedly agree, highly unlikely that it will at this point), it will still be the 2nd highest selling home console of all time (behind only the beast that was the PS2), even at the lower number. My point is, why support a higher number than is likely just for the sake of being 2 million higher when 102.49 million is a massive achievement in and of itself?
Also, just curious, but can you link where the 105 million production shipment you cited came from? I didn't come across that anywhere in my searches, and I'd like to see anything I may have missed that offers a differing viewpoint.