IanA – Apologies for turning up late to your new build thread.
I got these cheap and cheerful Reflector / LED Fog Lights from Ebay / China.
They have the option to be stop / tail lights, but I wired them together to create fog lights.
They are normal reflectors until you connect then to power, at which point they become very bright lights.
After adding an original Lucas reflector suround I had this.
Hope that helps.
Good luck, Paul.