This is a simple 3x3 door made to look like a bank vault. I made this door several years ago, but only recently decided to upload it. The design is quite simple, combining concepts from a normal "vault" door and a "cross door" to get the look.

There are 3 options for the back of the door included. The first just looks like a standard vault door. The second is a double sided door, so the back is the same as the front. The third is flat on the back like a normal 3x3 door. There are 2 of these with different timings. The first 2 backs have options for the corner blocks to more horizontally or vertically.