I worked on this mounting system for 2 months struggling with fusion 360 and working around my PCs limited ram capacity. I have now had this mount on my wall for 2 months and we have no signs of issues so far. 

This mount uses 4 m5x16 socket head screws to hold the shuttle mount base on the angled mount. 2 more M5x16 that screw in to Technic pieces in the aft landing gear bays. This ensures the model will not fall off the mount even with the every day vibrations that are in a house. The printed lego studs help as well.

The Hubble holder uses 3 M4x10 screws to assemble the two pieces and to secure the strap that goes around the Hubble body. The bottom piece is held in by surrounding Lego pieces.

The bottom base piece is printed vertically to help the layers not easily delaminate due to the pulling force of the model orientation. You will need to tap the holes with an m5 tap prior to installing screws. I hope you enjoy this model