I got the dark millennium falcon (75389) and wanted to mount it flat on the wall like my other version. They changed the landing gear on this set which did not allow me to use the existing mount design. 

This allows it to be mounded at most angles, just make sure the pegs that lock into the frame holes are pointed up. It is a little tricky to align it onto the mound but once installed it is very secure.

This may work with other millennium falcon versions but I do not have them to test it out.