Just a manual choke cable attached to a switch panel I bent from a sheet of 16ga metal from OSH. I drilled a hole through the plate for the clutch linkage at the firewall to run the cable.

The cable is the shiny metal line inline of the brake booster. I twisted the end making aloop, and attached a piece of metal (included in the choke cable parts) to the throttle arm(?). I then slip the loop on when I want to be able to use the adjuster. Not a perfect piece of workmanship, but it works well for 9 bucks.