Thanks for the number break down, I hadn't looked into it at all as far as what actual numbers would be correct. I don't think I care enough to have the vanity plates made and then reproduced in blue, if I was going to do that I'd just run the black and yellow vanity plates like I do on my Duster. Plus I think there's supposed to be a rule that they won't let you copy the pattern from a previously regularly issued plate, to keep people from having reproductions made like that. But I suppose someone would have to catch it.
Looks like it does limit my '72 to using only 6 digit plates. But that kinda makes sense, since before you needed the "base plate" plus the right year sticker. So like if you had a '67 you needed a '63 base plate (black plate) with a '67 reg sticker. So the blue plate is actually less restrictive, I just need a blue plate with 6 digits, which was basically anything issued from '70-'79 right?