It was me, not Laurence Harris, who asked for an explanation regarding the Hyamson collection. Laurence already knows because he used it!!
Like Michael Bernet I went to Google and typed in "Hyamson collection" and also turned up 3 hits. However I then typed in "The Hyamson collection" and it turned up the promised 130. I did eventually work out what the Hyamson collection is (a collection of documents donated by Albert (?) Hyamson in the mid 1900s to the Society of Genealogists). It did take some tenacity to find the information.
Thank you too for a more recent posting by Laurence Harris explaining fully about the Hyamson collection.
Thanks Michael for your comment - I heartily agree.