ADE (and most ereaders) normally show 'original' page numbers for some nominal fixed pagination,
even when they are showing less (or sometimes more) than an original page.
Make the ADE screen small and you will notice the page number does not always increase as you page through.
ctrl-shidt-H (menu/Reading/Show Page Numbers) also shows them on the page itself.
You can't be sure they will exactly match any particular print copy so worth checking, but I suspect they usually will.
Thanks again. I tried; however, unsuccessful. I will resort to manual counting from Preface onwards. It is my only luck.