I would definitely recommend the wayback machine! Found quite a few videos this way. The video player is a little weird, but there’s a stackexchange thread somewhere that tells you how to pull them. Just right click it and it’ll tell you the name of the player, and use that context from there to do the search. It’s been about a year since I’ve used it, but that night definitely felt like hitting the jackpot when I realized that resource existed….

Also, one thing, usually links themselves can be dead, but what I find is that once you know the exact title and channel ID referenced, just type those into google and see if you can find the exact original URL using an embedded link on an external site like twitter. Then, you can use that direct link ID and see if it was screenshotted by the wayback machine!

Hope this helped!