Yep ... got one. We are looking at triple core brass. Mine .... when built will be the width of the fan shroud, just to keep it tidy. I asked my mate, who is building it, how it is going the other day and he said "its moving along". His partner clarified that it had moved from one bench to another to make some space.
I can't really complain as if he built it as a costumer job he would have to charge me for it

I have the same reasoning as me in that I want more air flow down the sides of the bike.
Going for a run around SE Qld next week ... had hoped to have it on but that won't happen. Doing Adelaide to Darwin and back in August ..... I want it on for that. The last time I did that run I nearly burnt my leg off which made me think about air flow over the headers on 40 degree days.
This is a picture of BSA Bobs "little radiator" at RDU a couple of years ago. Not good pictures but gives the idea.