again, my concern is doing repair work near the top of a post, above the crossbeam mortice. I see this as the area of the post that has to work the hardest when the wind blows.
I was asking if you would use the repair you wrote about at the top of a post?

what i meant by cavity is that there are places where it would be stronger to "patch" the posts, than it would be to cut off the post and add a new piece of full sized timber.

I appologise for my confusing writing,
and thanks for your replies
-mark.