The BBC Archive YouTube channel claims to have existed since 2018, but their videos only go back three months. I discovered them just yesterday. My favourite thus far is an interview with J. R. R. Tolkien explaining the writing of The Lord of the Rings. Also featured is the Shildon steam celebration of 1975, which includes an interview with Wilbert Awdry (strangely called “William” in the voiceover), and at least two short documentaries about the making of Classic Doctor Who.
It’s too early yet to know just how many videos this channel will post. If it’s anything like British Pathé I will be greatly impressed.