Dmt also has hose kits. They are paper wound wire. The OEM hose had a smaller end on one of the hoses. The aftermarket are the same size but have a a reducer.
As for doors.
There is one door that forces air to the defrosters and another that blocks air from entering the box all together.
I...
Is the engine in your possession now???
You going BB!
I got a 66 383 from a 66 Fury II and 727 from same. I changed all the front accessory drive parts to be 67 up versions (its going in a 67 Dart GTS clone) easier to get the right parts when it is all from the same year.
The 50% probably refers to the glossiness.
In the FSM there is a paint section (at least in 67) some of the black says 80% gloss.
Ask you painter what exactly he is referring to.
I just checked and I can't find the 80% reference. I know I read it somewhere!
You could probably make one from spring wire.
I mistook the clip that holds the pin into the gas pedal for the spring. The clip 14-01-08 is only an anti rattle
Many of the basic parts water pump etc might be purchased at many auto parts stores.
Your local stores might be able to order them in.
You could always go the cuba route and use whatever parts are around. Like do an engine swap from a Fiat, or the like