heard so much about abba stand
will they fit nc21 cheers

The Abba stand is more or less universal, it just has different adaptors to fit whichever arrangement of nut and bolt you have securing the engine to the frame. On the NC30, a pin on one side goes inside the hollow bolt, and on the other side a cup fits over the nut. Even if they don't happen to do adaptors specifically for the NC21, they're really simple items which any machinist could knock up.

I just had a quick look on their website, and they do some for the NC24. I'm not sure if they're the same frame or not.