Are you sure? If you're not allowed to discuss how to make your own of anything because a sponsor sells the same thing there's a big problem.
We'd have an issue in many, many threads. This hobby, to a great extent, is about assembling things from parts, whether purchased or made by hand.
However, I believe in this case that the original commercial source had patented it's design and this may be where the issue lies. Copies of that design are not allowed unless licensed from the patent holder.
Mike
