Whitehouse K17 mods...

[Ninemeister_imp]

The White House side panels seem to be made from pressed steel which is then hand finished prior to painting, likely with a fair coating of filler/primer given the feel of the panel.

Hand making a similar pair out of steel is not out of the question, then shaped using body filler to achieve the desired shape before taking taking moulds from the finished parts. From the moulds you can then make production panels in GRP or Carbon.

The corner brackets could be replicated to copy the mounting points of the original side panels.