I've this basic 3D maze type, and some combinations and size.
The rules are very simple. Go from start to end, using this easy rules:
Puzzles books contains 5 full page mazes, and solutions. You can buy it with PayPal, and I'll send it on email.
3D Staircase Puzzles Book 1
3D Ladder Puzzles Book 1
I've combined the 3D mazes plans with my burr puzzles to make a "real" 3D mazes :-)
I like the Lord of the Rings saga, the castle puzzle ideas came from there.
I share some of my knowledge for your pleasure :-)