Trying a little experiment here if there is interest.
I've borrowed mostly from the Okajima list posted in this thread and added some from GPA Analysis, searches etc., and put it into Google Sheets.
There are 88 books currently listed. https://docs.google.com/spreadsheets/d/13BdqOViCfTnUYrJtPgQfkeppmRMjFe_1VZFMHZGFN88/edit#gid=0
When you click the link it will send me a request to share the sheet. Once shared, people can collaborate as a group if folks would like to continue attempting to document known Okajimas.