I personally hate to see a restorable car parted out. some are not feasible to save. but one thing a parts car is great for, and that is place to go to for nut, screws, wiring parts., to check out is a host of things IF your car is not very complete. this is not so important after years of parting out boners, collecting all kinds of parts.
This is why i hit the boneyards at least 1 to 2 times a month if i can. I buy the parts i need for my projects, and parts i can resell to people here that can use them, allowing me to buy more needed parts.
Honestly other than the heater box, sunvisors, A pillar mouldings, vent windows and windshield, there really isnt very much else that crosses over to your 69.
I'd look for a non A/C heater box for you, but everything out in my local yards has A/C
