Bass1 I have three Brisons, and I have yet to find a good way to connect a servo choke without a bell crank. And as you stated, there is a lot of friction/resistance on this unit. Therefore, I have just attached a HD ball link to the choke arm, then drilled a hole in the cowl and ran a 4-40 rod with a "o"bend on one end and thread it into the ball link. I also slip a piece of fuel tubing over the 4-40 rod to keep it from vibrating and damaging the cowl. Adjust the rod so the choke when off the rod only sticks out of the cowl enough to grab and pull it. Pull out, choke on, push in, choke off, easy to get to and functional.

Sorry I did not have a solution to your post, just wanted to tell you I have not been able to solve the same problem.