Sorry for commenting on a random post—I can't figure out how to post a comment on your blog or send a PM (I'm on mobile but using workstation version of the website).
I wanted to ask about the copyright/left licensing of your prototypes. I'm curious, but not going to make a purchase when I don't know whether or not I have legal permission to use them, and in what ways. (You should probably put that information on the page, but maybe I missed it.)