Modular display stand for Speed Champions, parameterized for more customization including a parameter for the tolerance for a good fit no matter how (in)accurate your 3D printer is.
The attached STL files worked on my printer. I would highly recommend printing part of the bases first to make sure the connections work, if they don't fit or are too loose, simply download the .f3d file and in Fusion360 go to “Modify > Change Parameters” and change the “Tolerance” parameter.
Besides tolerance, most of the model is easily adjustable using the parameters. To print your customized model, go to “Mesh > Export > 3D Print” and save as 3mf/stl.