Few others I think are missing from the database.
HOLIDAY GIFT BOX KHANS
Sultai Charm
BLANKS
Blank white card - Front is black border with white face
Blank grey card - Front is black border with light grey face
Blank grey stripe card - Front is black border with white and grey striped face
I have the white handy, the other two I would need to find if you needed images. Whites I have seen come from several sets. I think the grey I got around Ice Age and Stripe was around prophecy or invasion (maybe).
Also have heard Unhinged had a solid silver blank. Never seen it though.
DRAGON'S MAZE PRERELEASE EXTRAS
-Two Maze achievement Cards
Champion of the Maze
Maze Runner
-Guild Symbol Cover cards
Each Sealed deck came with a guild symbol insert card.
Only two possible backs I know of. FNM and Planeswalker Points.

Thanks for all the hard work!