It doesn't even look like a plain 21W bulb, but the smaller one, maybe the typical 5W, maybe the less typical 10W. I'm pretty sure a good triplet of white leds would produce more light than the bulb. If they did it the triplet red leds for the fog, why not that one.
Yeah this is a pain in the are because I have a spare led bulb from my 66 plate leon but because seat have been extra helpful in changing the bulb type I've got to source a different bulb that should have been led from the start!!!!!