maybe this could help?
From The Lost Media Wiki
hi, english is not my first language but i wanted to give something that may be helpful i guess idk. I was trying to search for pv re-uploads on YouTube through the wayback machine around 2011, I couldn't find much but in the search engine, when I tried to just search with the word interface, "interface vocaloid" appeared as a suggestion. I don't know how effective this method could be, but maybe you could find something by searching each of the days of the year 2011 on youTube in the wayback machine, has anyone already tried to do it? I hope this can help in some way...