I'm sorry but I disagree with what I think you are inferring as the 25 263 is consistently lower suggesting that smaller diameter axles have been fitted, with larger diameter axles probably fitted to aid traction (gearing).
I have never been able to figure out what people are going on about the 25's as far as I can see if it walks like a duck, quacks like a duck and looks like a duck, it's a duck.
Pete