the reason i ask about the method of forming the covers is the vacuum forming mothod requires a different type type of part, as you can't use vertical surfaces as the vacuum forming process causes unwanted webbing at the edges and the bends.
well that is what i seem to remember form a few years ago.
maybe it would be a case of just me creating the 3d model as per the original cam cover and the company in question can then tweek the design to be manufacturable in there facility and useing there vacuum forming process