Excellent photos! Could you show where/how you fastened the other side of the sliding bolt?
What kind of fasteners did you use to secure the metal plates? Are they rivets? Screws? Bolts? I see they didn't go all the way through the door and am curious.
If they are bolts or screws, did you add any glue to the process to keep any vibrations from working them out?
Are you going to put a handle on the outside to make it easier to pull open?
I know... questions questions questions...
Keep up the good work!