9.25-16 tyres - What's the story?

[Tony Smith]

I thought that maybe the Simex tyres were perhaps just a "Built big" tyre, so I compared a few original WW2 9.00-16's.
Here is a NOS Firestone 9.25-16 up along a WW2 (worn) Firestone 9.00-16 sand style tyre. The 9.00-16 has lots of flat spots and is not inflated, but it seems to be a larger diameter and is definately wider (could it be the sand flotation design? If larger than 9 inches, why not call it a 9.50 or 10.00?)