13th Century Puzzle Initials

So far I've been using the British Library's digital Manuscript collection to do a bit of research into Puzzle initials.  So far, I've look at 55 images from 40 manuscripts of French or English origin, that have puzzle initials that are from the 13th Century and I've found a lot of similarities in the components used to draw the initials.  I've gotten a little class handout written up.  I hope to continue this research while branching to other centuries and also different library collections.