Thanks John, I hope some find it useful. Now that I understand the process they use it helps narrow things down. Everything I'm finding so far is either too yellow or on the orange/greenish side. If all else fails a sheet of aged WMP it is and call it good. LOL.
Glenn,
Fascinating post. Thanks for all the detailed info. My assumption is that the top clear layer is printed or dye sublimated using CMYK processes. That would only make sense. I am also pretty sure from discussing this with Andy Foote that he will print (have printed to be more accurate) whatever color you want. You are also correct in that this process works with sparkles (be it glass or glitter) as well as pearls. He has a great product but my guess is that his market is tiny indeed.
While not vintage, I saw a Crush kit the other day going out to rehearsals that was a red to orange fade glass glitter. Kinda made your mouth water. It made me want to call Andy and order some. By the way, I am also pretty sure he will send sample sheets on a loaner basis. He has the samples you see in the photos on laminated cards.
Lastly, that is very kind of you to offer to loan out your PMS swatches. Most guys would have no idea what those things cost.
Great post.