Brison copied A&M, as did Fox...The shine came later....The bell crank in the original picture is A&M..Early A&M engines used Sachs cranks, then changed..That's when the decline started...That bell crank system was changed by Brison to the shiny aluminum one they use now..
Brison now guarantees their cranks for 5 years...Whatever they did seems to work....
Have you checked the timing ? That long bell crank will move the ring pretty far from idle to wide open..
If that color on the top of the cylinder is paint it's definitely an A&M..