I kind of already did that, though it’s quite possible what you’re working on will be better. Mine is a clamp that holds the Handy with the help of some friction material between the two. I use some neoprene rubber pieces. One could probably also use some big rubber band pieces. The base is a standard VESA mount.
The STL’s can be downloaded here.
Here are what the parts look like:
And here’s a quick and dirty picture of it attached to the Handy:
I’ve thought about extending the size of the clamps downward and adding a floor for the Handy to rest on, but haven’t gotten around to it yet.