How to make an ACE without moving ISBN?

[Keith]

I have in hand a copy of this book from the SFPL main library. We have two editions in the system already:

The most current cover with the ISBN attached
1973 cover as an ACE

The one I have in hand was printed in between those two editions, and here is a photo I took with both the cover and the barcode visible, same ISBN 9780156701532: https://www.dropbox.com/s/slz2kqcx1aj...

(I attach that image here per https://www.goodreads.com/topic/show/... )

If I use the ACE creation link https://www.goodreads.com/book/new_al... I get a note that the ISBN will move to the newly created ACE, but my understanding is that the ISBN should be on the current-cover edition per GR policy, which it already is. And as shown in the above photo, the ACE I have should have the same cover image as this Harvest edition.

So I could use some help with figuring out how to get this in the system without violating any policies in the process. I am equally open to being instructed, or having someone else just do it—I generally just stay away from ACE creation in the process of my Librarian work whenever possible anyway. We all have our specializations, right?

[Scott]

Add a new edition, and leave a note on the record indicating that it is an alternate cover edition of that ISBN.