Here's a pic of my DO-17 hanging from the ceiling using the technique I described earlier.
The plane is hanging in the loops of nylon by the wings and by the tail. It's hard to make out the thread, but you can see the three thumbtacks. If I want to change the position of the plane, all I need to do is relocate the thumbtacks. On this model, there are some radio cables running from the tops of the two fins, so I had to put the loop around the tail before I added the thread. When I have to take the model down, I just pull out the tail thread thumbtack, and put it in fresh ceiling when I put it back up.
Here are several models hanging using the nylon and tack method. Geez, I need to do some dusting!!!