I'd be extremely skeptical...and think some of your guesses might be right, Orient...
Part was superceded (for a reason); might be a return that for whatever reason, can't be sold again; or, I'm also wondering, whether they might be replica/rip off parts that really didn't have the bmw logo underneath that was scratched off (how would you know if it WAS scratched off...might just have been scratched!)...coz it's made in a country, by a company, that is great at making perfectly fine 'looking' replicas.
Might be cleaned up parts from parted out cars...maybe reman, maybe not.
Anyway, whenever I'm skeptical about things like this, I just stay away. Very few parts are worth risking the try on our cars...especially if it's a hard to get to part.