Now here's an intersting page for you... all the FIA approved rain lights as of the middle of this year
http://www.fia.com/resources/documen...ain_Lights.pdf Of more interest perhaps is that the little round one that DT say isn't approved seems to be the same as the one half way down the second page specifically listed as supplied by Merlin Motorsport at Castle Combe. They currently have it listed at about £45 inc vat.
As for the retro look midgetman, I used a rectangular grid led type light and cut open the casing to retrieve the circuit board and light grid. I then took the bulb and lens out of my old rectangular 21W chrome housing and bunged the led grid in with lots of clear silicon. Has worked a treat ever since and looks the part too :-))