Heater and ducts and vents

[sky56]

Hello all i have a 77 k10 and it is my first chevy truck but i am not new to the car world. My k10 has the custom deluxe trim/package and i have some questions in regards to my heater and all that. In the truck i have the heater unit that has the 3 speed switch on the left hand side and the selector switch to the right for off/heater/def and below that the switch for cool/heat.

I am curious to know that since i have the lmc truck catalog it appears that i should have ducts and vents and all that (page 132 of the newest 73-87 catalog) I have the opening but no vent in 2 spots 1 to the left of the headlight switch and the other above the heater unit. To the right on the passenger side is a wood panel that says custom deluxe on it and covers what would be 2 poss vent spots according to the diagram.

So am i missing 2 vents and some duct work? or no because its the custom deluxe and i dont have factory a/c? and if thats the case do i have the wrong dash bezel? any info on this would be great. The heat works great in my truck and im not a fan of vent heat because it dries my eyes out but i would like the interior to look better of course. Thanks to everyone who can shed some light on my confusion. Take care