Sorry I'm coming to this late. WRT the heater valve, it confused me why, on the TCs anyway, the valve had a 'step' in it such that if it were closed, you had to overcome resistance to open it but if you opened it you generally couldn't overcome the resistance to fully close it. There must be a reason. Anybody have any ideas or solutions (I used the same valve when I rebuilt my car)?
Congratulations on getting the 'birth certificate' for your car, Stephen! You have a lot more documentation on your car than I have on mine - and I am the original owner! I do have the original window sticker but it's not in great condition. The lack of documentation on the earlier cars, especially, would make it hard to document a car's originality for a concours competition!