65’ C10 wiper knob removal

[nxtruck]

Guys,
Can anyone tell me how the wiper knob is supposed to be removed? It’s a single speed wiper switch and, as far as I can tell, the switch and the knob are both factory pieces. I know the replacement knobs are held on by a set screw, but this knob has no set screw anywhere on it ( and I have looked at it a couple different times ). I’m considering trying to just pry it off of the switch shaft, hopefully without damaging the shaft or the switch. At this point, I really don’t see any other way this knob could be held on to the shaft, but I thought I’d ask to see if anyone else has ran into this.
Thanks in advance for any help!