So, have you ever wanted to know how to place a trade skill object? Well, it's really quite simple. You really only need to worry about the icon, model file, location, and heading.
Doors in the database are stored in the object table
While in game, do the command /loc. Now I belive that loc is listed as x,y,z but objects use the cords from the real map. So x and y are backwards in /loc z is height (Not in real 3d, in real 3d x and z are the level plain and y is up and down.)