Mine's only been used twice; once about 20-30 yrs ago for bob whites & once this fall for some of my own RSL's Only trouble I had was finding the "sweet spot" on the temp screw.
I found not to use the locknut too much
If you mess with the nut when adjusting it throws the wafer of kilter, or off it's axis
makes it tilt one side or the other, throwin it off