Sorry, never had the stuff. The LCBO sold a few bottles of the CL 21 a while back. I think Lord P got a bottle and (if I'm right) could fill you in on his impression. Other than this, I noticed some threads going back a while, that the main top dressing malts included Macallan and Tamdhu.
That's all I know about the blend. Sorry I couldn't be more help. I think Admiral tried the NAS version a while back.