Hi, there, sir. I can't do from your .STL anything useful. That model is not editable, no one can edit properly .STL files, no for $30. I can create, however, from scratch a full editable file in either Solidworks or Inventor, provide the files and if you want to keep the work, and hire back me again or anyone else, the file can be edited properly without wasting time. I can also provide a neutral editable file, with the difference that the parts aren't constrained one to each other.
For 250$ you can have the files you want for the closet close to the pictures you sent me, with some minor editions.
Thank you.