I've never overlayed a M-16 extractor over the cut for a Sako, so I don't know for sure. I think the pocket for the Sako lug is milled all the way through to the firing pin hole, and the hole for the plunger/spring that retains the Sako extractor is drilled about a half inch deep along the axis of the bolt. It might be possible, but it seems like there would be a lot of extra holes left over from the Sako extractor cut.
I would simply lay a M-16 extractor on top of the Sako cut, and see if it might work.
Maybe Shortgrass will see your thread and reply.
Tom