This is a vertical display stand for the Space Shuttle Discovery. It is designed in a way to be assembled by inserting the squared peg into its corresponding socket on the base part of the stand. If the peg does not insert at all or does not insert easily enough to fully insert it into the hole then I would advise you to sand one of the faces of the peg down until it fits snuggly into the hole.

For mounting, simply just align the two display pegs on the vertical part of the stand into the original holes on the bottom of the shuttle, then insert the technic axles through the holes and install the modified 2x2 plates to secure them to the shuttle, make sure to do this for all five holes to prevent spontaneous disassembly and tears.

Additional parts needed: 

5x 10L (80mm) technic axle (Part ID: 3737)

10x Modified 2x2 plate with pin hole (Part ID: 2444)

Recommended print settings:

0.2mm layer height

15% infill

2 walls

PLA or PLA+

If there are any complications or discrepancies with the design itself be sure to let me know so that I can make any necessary changes.