Because there is no practical method for doing this.
While it may be possible to do what they describe, it won't be anything like owning/operating an experimental amateur-built aircraft.I stumbled across this page, http://www.v8seabee.com/regulations/united-states.html , which described in general how to convert an old salvage plane to experimental.
Has anyone followed this route with their project, and if so, has it been as straightforward as that article would imply?