Rather than move things around again, perhaps it would be better just to give indicative labels on the index page, as Sue suggests.

I also agree with Sue that, notwithstanding the reinstatement of material that went missing, Brian's work should be preserved and maintained as he left it, so it can be recognised as it is, a legacy of his life's work. It would be wonderful to continue the process and increase the available sources for everyone, but in my opinion this should also be separately recognisable as someone else's project, and not amalgamated with and lost in amongst Brian's.