Now I have used plenty of bodyshops but was impressed when I asked if they wanted the paint code, reply was "No, we mix the paint ourselves to match the car."
Superb - As we all know paint fades etc due to age and weathering so exactly what I have been waiting to hear for years. Usually they ask for the code
I agree with you about wanting the match done right! It's often hard to see in photos but I think we get enough of an idea from that one. On my monitor, the rear panel looks more 'blue' than the door. The rear bumper on a 166 though tends to be at an angle to the side panel and accentuates the colour difference more, I have noticed.
However, I've had some bad experiences with paint shop matches in the past. I really prefer people to mix the proper colour to the recipe - sorry to disagree... Take an example of a paint shop match for 'Bianco 210' that I had once. The recipe even for a shade of white has all sorts of primary colours (green, black, yellow etc) that you wouldn't possibly add by guesswork. Therefore under certain lights, the match might be very good, and under other lights (say, those that bring out the yellow), it might be awful.
Another problem I used to find was with something like a Rosso Corsa 140 FIAT Uno, where the paint 'faded' to orange or brown. The paint shop would match to that faded colour. Then when I got the car and polished up the panels with cutting compound - guess which parts were glorious red and which parts where shiny brown?
So I would rather have the original colour, regardless of what other paint on the car may be like, and in my experience, metallic colours don't fade like solid colours do (or did).
I expect that your paint shop (and, I'm happy that you have found a good one!) probably used a bit of both techniques - perhaps they found the code was incorrect when they did a 'crosscheck' against the recipe. I have seen a Tipo with the wrong colour code on the label as well, so I think you're right that there was a mistake! There used to be tiny changes between the years - Rosso Chiera 854/F is, for instance, very similar to Rosso Corsa 140, and just to really confuse things, I saw paint labels for Rosso Corsa 854/F... and Rosso 140.
It is a very good sign that your shop bothered to check carefully before plunging into the job as perhaps someone else previously did...
Anyway - I completely understand your decision to get the job done... My 166 was painted by someone who had perhaps never sprayed metallic paint before. Since it was so blotchy and dry, I guess that they had no hope of matching the existing paint, so they resprayed the WHOLE car - even the sills!
My two left doors seem to have been painted in a series of random swirls and bursts - so the paint was all done at the same time, yet looks different colours in some lights...