You won´t find them in MERP because i made them up!

Or let´s say, they are based on works from the fanmodules group and other minds magazine and i reconstructed their name in JRRT´s teased north-Avarin dialect. MERP only has the Luindrim of Luindor and other minds magazine identifies the North-Elves as the Hwendi.

That's actually a relief! That means I haven't completely failed at googling. Thanks for clarifying!