Hello Will,
I was given your name as I am trying to trace a number of photo agency/publication archives and he suggested you were the man to ask. Having looked at the Press Photo History Project website, I guess he was probably right!
I am interested in using some photos I have seen credited to those agencies and hope to be able to source them through an operational agency that might happen to hold rights to the collection.
The agencies are: Full details on our Press Photo History Project site