Create New Page From 404 "Page Not Found" Error

[jwzumwalt]

This isn't really necessary. You can just create a page, make the custom slug 404 and it will override the built-in error page (GS wiki)

You can do the same thing for 410 (Page Gone).

I don't understand your answer - so please provide a simpler example that provides a create new page link from the 404 error.