[Savage GT]

Just a thought, but sometimes getting 10mm tyres means sanding or slicing as tyres that say they are that size do have a bit more sometimes.
I prefer not to slice /sand tyres width whenever possible.
Also a lot of the NSR tyres (my preference as a few others) for classics only go down to 8.5. And most Slot It tyres don't even go that narrow. There are alternatives obviously, but I prefer using either of the above brands personally.
Might it be an idea to allow 10.5 when you want 10 and 9 for 8.5 mm as maximums ? Thinking the GT proxy also could benefit from that ?

Also think maybe you are too generous on max widths across the board for this proxy, personally I would have thought 55 max for event 1 and 2, 57 for event 5 under 2L and 61 over 2L ?
Just thinking it could make a larger range of cars competitive as its easier to narrow axle widths on the wider bodied cars.

As always, just my thoughts, and obviously will comply with your decisions :)