Go to Wally World and get the dimmer switch replacemnt dial. It is $1 or less and comes with 2 or 3 adapters you can put inside it to make it fit to different size "sticks". Works perfectly and no drilling or construction needed.
So i read your post and I was wondering if anyone would know how to do this on a Hova-bator 1602 I'm not sure if they have a different knob then the LG