Here is a video on such an conversion. It shows the ejection of a spent case on the fly, looks like a mag to me.
http://www.youtube.com/watch?v=EDf_J7k2ZagThese folks appear to offer a conversion if you choose to look at their wares. I have no idea of what it looks like for real; never persued it further as to content. Just thought it was interesting on a subject that is hard to find worthwhile info on, I have no idea of how the conversion is, works, etc etc.
I have done both the lifting arm and movement within the breechblock itself conversion styles; never done an offset shank. I did the lifting arm first(made the arm from scratch), but have come to the conclusion that the firing pin movement within the breechblock is the way to go. Once you have a conversion, I think you will enjoy it. Feels like full sized rifle in my opinion.
The 22lr takes some dexterity to load, but not a big deal. I would think that the mag or HMR would be easier to load(longer case), with the accuracy going to the 17's because of their bullet.
I am starting to think of a switch barrel no.1 in 22lr/17HM2 and a secondary No.1 in 22mag/17HMR FWIW. Could just have four conversions, but now that Winchester is bringing out the 17 super mag rimfire, perhaps a fifth? These things never end, and glad of it.
One thing about the no.1 action, it is very flexible, and relatively easy to convert in caliber, even the rimfire application.