Lo and behold, it’s fresh: bitbucket link, greasyfork mirror. The script should automatically add an “Import into MB” and a “Search in MB” buttons on pages like Hyperion Records
As usual, caveat emptor, it seemed to work on the few releases I tried, but ping me if something looks wrong. I didn’t try to import barcode and release date since those do not appear on the release pages as far as I can see.