Just did the new Mojave dark update, went into my photos to edit the photo book I was working on - unable to find how to edit it and complete. I am now seeing that apple is no longer publishing photo books?! Is my work lost?

Just did the Mojave dark update, went to continue working on my photo book I can see the work I have done to date but can't find anyway to get back into it to edit and complete

That looks like you have been using the Photos for Mac application. Photos 4.0 on Mojave does no longer have the tools to create or edit books or any print projects like before. You can onIy use project extensions to order print projects from third-party providers.

Here is a recent user tip by OT: : Old Toad: Post 9/30/2018 Printing Options for Photos

The Mimeo Project extension allows you to convert your existing book project, see the paragraph on converting projects in this document: Create and order print products in Photos with Project Extensions - Apple Support

also: Use Project Extensions to order print products in Photos after September 30, 2018

Do you still have iPhoto 9.6.1 on your Mac? If you do you can drag the migrated iPhoto library with the .migratedphotolibrary extension onto the iPhoto app and select to open it again in iPhoto.

You can then finish your book and do a Print to PDF of it.

Since Apple is no longer providing print services you can upload your PDF to PrestoPhotos for printing and binding.

In which App? iPhoto? Photos? Something else? What version of the App?