As part of an internationally dispersed team, I have first-authored a text (along with other authors) which is meant to become a chapter of an academic book. My text was lightly edited in a process of file exchanges whereby the author names were in evidence in the files under the title of the chapter. I have done this as an employee of organisation A among multiple organisations which contributed chapters to the book, as part of contract work with a customer organisation B.
However, organisation B is taking a long time to have the book published. The longer it takes, the more I am in doubt about the protection of my authorial credit in the chapter. For all I know, organisation B could be editing the chapter substantially and deciding to remove my authorship as a result. It's difficult to tell also because the contract between organisations A and B has terminated, and as a result I am also no longer an employee of organisation A.
What steps can I take to protect my authorial credit of the chapter in the book to be published and to protect myself from plagiarism if my authorship is not acknowledged in the book once published?