Thanks to you all. As to getting it apart, I just used transfer punches of various sizes. Take out the nib first, then the centre band part. Same idea with the top. That was the easy part. Both the top and bottom parts get drilled with two drill sizes. The upper is pretty easy after that. Just like any other closed end turning. The tricky part with the nib end is that the material is only a couple of thousands thick at the nib end and the center band end.
I'll take some time and do up a quick tutorial asap. Please keep in mind, though, that this is my first attempt at any Sierra, so I'm sure that others will know better ways of doing the same thing.