Did a test it & it will clear, someday I would like to build the right bracket, but that can wait for now.
Btw, anyone able to provide a correct pulley size for the motor for sickle drive?
Looks like it's working very well! I think you can mow an awful lot of grass using very little fuel with one of these sickles.
I don't know the diameter of the pulley without checking but do know that it is the smallest of them. And the belt specified is 1/2" by 107". (for 60656) The easiest thing for the rear bracket and lever is to find a 65 parts tractor if possible.
And you re right, the pic above (blue tractor w/generator) showing the right side belt tightener is something I adapted from a 66 era tractor. I mounted it to the front axle at it's upper hole and shortened the tensioning rod to fit.