Here is the tree topper I designed in solidworks with my two boys.

Update: I added a version so you can wire some strip LED's in the back (see photo). I had some LED's laying around and a 12V wall wart adapter and figured "WHY NOT". There is a passage in the base to route the wire up to the LED's, and a back cover to cover over them once installed. The LED version requires support because I recessed the cover into the back 1mm, but support removal should be pretty easy, and it doesn't have to look pretty under the cover because the backing plate will eventually cover it up.