The prototype you have shown looks promising.
The camera can be improved by choosing larger diameter knurled locking knobs. Most buyers prefer a ruled ground glass instead of a plain one.
They want to know the species of wood used in the construction of the camera as well as the metal used for the hardware.
Polished and lacquered metal parts make a wooden field camera especially desirable in the eyes of most buyers. Polished and lacquered brass fittings are especially desirable.
Likewise, the choice of red bellows is also appealing to many.
The camera will be more desirable if the bellows are attached in a way that makes removing and replacing them fast and easy.