I'm not saying it won't work, because I remember installing one before in an OS, but if you take off the head button with the Nova plug installed, you'll see that the Nova plug taper is smaller and it doesn't fit flush. It also will not keep the contour of the combustion chamber smooth as it should be.
On the Nova, the OS plug will push the button chamber in to get the larger taper to fit correctly. This will now deform the top of the combustion chamber on the Nova button, so as it stands, they are not inchangeable.