Thank you very much for all your help.
I have been trying to find Wylie O'Hara Holahan's details but it has proven to be quite difficult. The closest thing I have come across is the library of Pennsylvania State University. I have sent them an email asking for any help they might be able to provide regarding the purchase of BUtterfield 8's translation rights into Spanish.
Would you know how to contact O'Hara's daughter?
Many thanks all the same for your prompt reply and all the information,
Reply to Lucía Barahona