Turn signals not cancelling

[ukc10]

Hi
I have a '71 c10. non tilt, and the turn signals do not cancel. Looks like the white plastic operating arm has been replaced but the problem is the arm has a 1/8" gap from the cancelling cam when in the on position. I am unsure if the replaced part is complete and the correct one for my truck can any one confirm this. Also if I need a new part is it available seperate to the switch assembley.











Thankyou.