Onshape CAD is here https://cad.onshape.com/documents/7a9b774bbfeea66681912ec1/w/cb05c87cbedfe563a1850a33/e/10afc9eaa87fa1cf0d79c53f?renderMode=0&uiState=6839e85915650411b75713c1
The author remixed this model.
Loosened the tolerances on where the two parts join together. Filleted the edges so they're not sharp.