Just something I had been up to ever since the snapshot that featured updated item frames came out. As I mentioned in the video, I am not the first to come up with the idea, but the redstone component of it is completely mine.
For anyone wondering, there is a video of me building this setup with the new invisible blocks, just to show you that it can be done, and the link to it is right here:
/watch/0d53G_12uej23
And if you want the world download, I have provided that as well:
https://www.mediafire.com/download/2wtctqo3dzdz404/Combination% 20Lock.zip
Hope you enjoyed this video,
-Dan