With a very big thank you to Hans Kremer, him of the ANPS. He alerted me to this site which has all the Arc de Triomphe answers I was looking for. A great array of all the plate numbers. Note that they are all different, as we figured they would be. On the bicolour set you can see that just the one plate was used for the Arc design bit of all the values, and that separate plates were made for the individual values. A lesson in stamp production!