Thank you, Kevin. I understand that there is no official institution to verify the uniqueness or distinctness of new cultivars proposed. Peter Diekmann introduced in 2011 a forum thread intended to post new cultivar proposals for discussion among the members of sempervivum-liste.de. A helpful tool that unfortunately was never used until now.
I particularly like this seedling - it's getting better and better each day. Still much too early too say how it will turn out in future, for me at the moment definitely a keeper.