I remember when I selected a paint for my roof and interior of the Safari I grabbed three or four different pieces that I thought were ‘original’ to colour match to… like the inside face of the cover panel for the boot lid lock that has never seen the sun…. Well, none of them matched! They were all slightly different so I picked a colour I liked and was about ‘average’.
The French I guess

- maybe painted on three different days or different places. Who knows.
I believe that's the case with many older model cars.
Most other forums than are full of threads on the right shade of paint. For a 64-66 Mustang for example, the engine bay, or the sway bar brackets, or the sway bar itself, the engine pulleys, the generator, etc, etc. The reality is the parts came from everywhere, all semi-gloss black, but some were sprayed, some were dipped.
The general consensus in the early Mustang world is that "the greater the variety of semi-gloss black finishes there are under the hood, the more original it will look".
It would be naive to believe that Citroen hung up a set of tins for one car, painted or dipped them, then hung up the next set, and so on.
They probably knocked out 10,000 of one bracket or cover plate, painted them, then 10,000 of the next one, and so on.