@OP, Let me just take this opportunity to congratulate you on creating this topic. It is always good to have easily accessible information, like this, in one place. I hope you will be able to keep this list updated. I especially appreciate the fact that you decided to omit the proven scam sites from the list (I hope this will not lure in a legion of trolls and sock-puppets in this thread).

I believe Curacao eGaming has a license validator, but I'm not sure about the others. Perhaps you can post an example of a gambling site with no license verification here so the community can help.