Interesting doc, thanks SoCal App. What I note is that it the 1997 FAA requirements on LP do indeed differ from the the current ones in that they tested all 4 skills, including writing and reading. As you probably know the current requirement only assesses speaking and listening.
While it's great to know the FAA were already thinking ahead back then, it still shows that there is a global discrepancy in testing. On the one hand we have the FAA relying on its previous across the board level 4, and on the other we have a wide variety of tests used across the EASA member states. I have personally experienced two sets of results from one pilot taking two different tests. Even though both results were a pass (4 and 5), if testing continues to be unstandardised we could end up with pilots actively researching "the easiest test" out there, and in worst case scenario, have "false level 4" pilots in the skies.