Brucey wrote:even a 1/4" spacer to the chainstay brace would help, and I bet the wheel would still come out provided you removed the RH track nut from the hub. Apologies if this is obvious but you ought to have a shallow-headed screw (pref csk into a larger washer) at that point, otherwise the screw head fouls the tyre.
The other thing that helps is if the mudguard bridge isn't under the seatstay brace; this takes up a few mm that could be better employed getting the mudguard higher up.
The mudguard SS clamp is as high as it will go and is mounted "backwards" so the clamp body is fwd of the bridge.
If the chainstay bridge was higher, the mudguard would be further away from the wheel. There is room on the brake calliper to lower the blocks.
I say agin, the design of the brake bridge is wrong. It's too low. If I ever have the frame refurbished, I'd get them to raise the bridge maybe 10mm.