I spent a chunk of August and September writing 400-character blurbs for the BFI Player - towards the end I was dealing with films with such unpromising titles as [Unidentified Park] (c. 1901).Tommaso wrote:Amazing! 28 hours of Mitchell & Kenyon films!
In fact, this is where putting this material out in toto can be very helpful - although many comments on the BFI's YouTube channel range somewhere along the "inane" to "flagrantly racist" spectrum (pretty much any footage of early 20th-century British life will attract the "See? Look how much nicer it was before the darkies moved in" brigade), there have also been some incredibly useful contributions that help identify places and people.
For an excellent example, look at the discussion here, where the teacher in John Krish's 1962 documentary Our School is not only identified by a former pupil, but his son later popped up to offer more concrete biographical details, such as the fact that he died six years ago. Researchers could spend weeks on stuff like this in the past, often with less success.