OK, I’ll bite.
Perhaps I can use the Seeed Fusion service to make one for me.
Please let me know when the 3D design is available.
Also please tell me which (free) 3D modelling software should be used.
After some Googling, I found several including Tinkercad, Sketchup and others, many of which seem to concentrate their marketing to architectural type of designs. Best would be free software that allows import of your STL file, allowing it to be modified.
The modifications I need would allow me to modify the height and interior layout to provide mounting of specific grove sensors.