I don't know how long this has been around, but if you go into the FAQ, it states:
"Can I get involved?
Certainly. Contributing new, verifiable data is the most immediate way to get involved in making this a better resource. Small additions or corrections to the data can be submitted via email. Contributing information on multiple "new" film stocks can be accomplished via spreadsheets, csv files, a database export, or through your own account on the system. Procedures for contributing images or PDFs are still being ironed out but those assets are welcome, too."
The only contact information I can find is via the LIbrapay donation link in this page which lists the author's email address.
Last updated in 2021 according to the bottom of the main page; I wonder if it is still actively being maintained, as there have been no donations as of yet on the donation link page.