Check out the HELP section to find out what and how they offer?

I only looked for a minute or two and found this link that explains a lot.

Google Books Partner Program Help

Its not necessary.....

Read This for more info.....

Adding books - Google Books Partner Program Help

Google states these lines for non-isbn books.....

"We are able to accept books without ISBNs for inclusion in Google Books. If you choose to upload a PDF without an ISBN, we recommend you upload a single file which includes any cover images your book may have. Your file should be named with only alphanumeric characters - we suggest giving your file the name of the corresponding book.

You may submit images for your front or back cover separately from your non-ISBN book's content file. We're able to process cover files in JPG, PDF or TIF format.

For example, if the title of your book is "Your First Book," and you have its cover as a separate JPG file, you would name the content and cover files as follows:
YourFirstBook_content.pdf
YourFirstBook_frontcover.jpg
YourFirstBook_backcover.jpg
If you have remaining questions about uploading a PDF file not covered by this page, please review our Advanced PDF configuration page."

This is the link to that page......

File upload guidelines - Google Books Partner Program Help