I bought an old gold Ghia L6.4 a while ago and thought that the red door inserts were replacements. So I looked around for a cheap model, condition not really important providing it had the right colour interior. I found a blue one with a cream interior but when it arrived that, too, had red door inserts! A gold one I bought cheaply with broken suspension also had red door inserts! I should have asked first.
Interestingly, both my old gold cars and the latest blue edition have not only red door inserts but also a red plastic unit supplying suspension and boot and bonnet mechanisms. The door inserts also do appear to be original and not the less well-defined pieces that part suppliers provide. This all arose because I can only get red inserts from the usual part stockist. They could do well for themselves stocking cream as well I reckon!
So it would appear that Corgi produced models with the red central unit and cream interior and, remarkably, red inserts. I know cream inserts exist because they're in a green metallic model I have had since new. However, I am beginning to think that I don't need to worry about replacing those in the gold car after all as they must be originals.
They do look odd, though, so I shall carry on looking for models that are inexpensive with the right colours and I can always make use some Black List models from the other parts. I wonder whether I'll find any with red interiors but cream suspension unit or doors? Surely not. But watch this space!