It is patchy, but remember in those days, these European directors used many names, as did their films, and there was no Internet, as you know research was done then with books, and imagine how hard it would have been to come up with some of this info. Not excusing, but I know it took the Internet to realise some things like HEY WTF JOE BLOGS IS ALSO JOSE BLOGAMISSIMO, etc.
It is fun browsing the database though, look some time at the refused classification titles, some are things like CD#356 confiscated Sydney airport, contains xxx etc