i think the existing elf heads "just" need to be tweaked, make noses more slender, jaws and chins narrower, eyes a little larger and more almond shaped. You don't need to totally remove the real world ethnic undertones, but the elves need to look like elves. rather than humans with pointy ears added.

I agree that elves look like humans to an extent still, because they're humanoid, but they don't need to look like humans in the same way. Technically, elven ethnicity is represented by their subraces (which, in the case of high elves actually covers three kinds: Sun, Moon and Star elves), so if you want to have some nods to real world ethnicities, they should probably be split between the subraces. Then you'd also want to limit the skin/eye/hair colours based on those subraces too.