When looking at your last three pictures with proposed designs, I got reminded of a project for a client that I did at the start of my self-employment. Could result in a nice open source hardware business model for your initiative
Namely, there's regaltischlerei.de, a German website where customers can order custom-made furniture in sizes they want it in. For their online furniture configurator I developed the function to show the piece of furniture in 3D in the browser. To try it: when configuring your piece of furniture on their website, you will get to a point where you see a 3D preview of the item, using the sizes, materials and colors you entered. Click & drag in that preview with the mouse pointer, and you can watch it from all angles.
Now for open source furniture like you want to build, a configurator software makes even more sense. Since the design is open source anyway, you can offer auto-generated CAD files for download to the customer, using the parameters the customer entered. Some will go and build the piece of furniture themselves, but others will order it to be custom-made by your company. The feature will make you well-known as "the company that hands out free plans for your customized furniture", and the publicity from that will bring in enough paying customers as well.
Just sayin'. Because I know making open source sustainable is hard, but I support it fully. (If you want to know more about the browser 3D tech, let me know. Can't share code, but expertise.)