This idea comes from DON HAYNAM after scraping too many knuckles adjusting fuel mixture on his Twin Cam.

Start with one standard SU wrench, a bent steel rod, and a Tinnerman type link clip. Put these bits together as shown, and you have a nice long reach adjustment tool for your H and HS type SU carburetors. If you can see where you're going you can use this tool to reach in from the front of the engine to turn the mixture adjustment nut, hopefully without bruising a knuckle.

I haven't tried this yet, but it looks like a long shank Phillips screwdriver with a bent end might make a nice handle, or just put a long narrow loop on the back end of the rod for a handle. Also the SU wrench with straight end might work better than the angled type.