Factory heater AC box going into a 1970 Charger

[70 sublime]

I am piecing together a project 1970 Charger I picked up a few years ago
Got less than half the parts to put the car back together with when I bought it ( former owner passed away and got the car from the estate )
So now would like the get the heater air box sorted out and in the car before the dash goes back in and have a few questions

Where is the best place to get a rebuild kit for the box that anybody could recomend ?

 

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Looking at the vacuum lines I figured out which one is the supply line that hooks to the engine
The line near the end is very hard and crunchy
Do not know if it full length still
How long should it be ?
Is there a good replacement hose that will do the job ?
If so are the hoses just pushed onto the white plasic plug or are they glued on and it would just be better idea to join a new section onto the the end after cut it back past the hard cooked spot ?

 

[70 sublime]

We have an old brake line

bleeder tool that I used to test all the vacuum pods with and they all move as they should
The only small hose I could find that would fit at all close on the white end of the vacuum plug was a windshield washer line and taped it on good to the brake bleeder

 

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Where does the supply line pass through the fire wall ?
I see there is a hole just under the voltage regulator is this the spot that I will need to find a gormet to fit ?

 

[70 sublime]

Last question for now
Looking at my first picture the heater AC box I am working with did not come with this car and did not come with the resistor spring gizmo that mounts into the box that changes the fan motor speed
Is a regular heater box resistor the same as an AC box ?

When looking at the back of my dash and wiring harness there was a set of coil resistors hooked to the ends of the harness but there was no fiber board on them that would have mounted it in the hole of the AC box so I have no idea what happened in the past but they did not look the same as the non AC box coils did and unsure what I need to find as this is the first AC car I have worked on