I use this to attach various things to a hot shoe, so I wanted an OpenSCAD version. Here it is.
Use the STL file if you just want to print one...
If you want to start with the hot shoe mount as a base for other things, use the OpenSCAD script and build from there.
(If the fit is a little tight, just grab a piece of sandpaper and lightly sand the bottom until it fits snugly in your hot shoe.)