Then again you can take the design to any carpenter and it won’t be too expensive to have one made. Judd who is famous first and foremost as an artist always had his works manufactured by others, I think he liked the idea of removing the artist’s personal ‘handwriting’. Ironically, he still played within the gallery system, where the gallery and the artist get to mark certain pieces as “authentic” and create limited editions.
Many timber stores can cut the material on customer's request, so you probably don't even need the carpenter - just order parts, to size, and bolt them together.