quick heater control question

[68c10owner]

I`m watching a complete unit on ebay that ends in 5 hours so I could use some help asap. My 84 heater controls are kinda stiff and hard to move left to right. My old 75 gmc was that way and the lever was actually broke off and stuff on heat. Is this a problem with the controls or is it the cables are sticking? Mine work but I`ve already broke the knob off of the fan but I can still move it and the heat/defrost lever is slightly bent and is hard to move. I guess what I need to know is am I looking at the right part to fix my problem? I`ll probably pick the unit up anyway if I can get it cheap enough but I want my controls to work like they did when these trucks were new. How do i accomplish that?