Here's a link to the index of JFK's personal papers, and you will find what you are looking for in Series 2 -4. It is in microfilm format, and was donated by the US State Department.
http://www.jfklibrary.org/Historical+Re ... _personal/
Luckily, my dear old Dad is still alive, so I don't just have to rely upon Mac's accounts of life aboard HMAS Shropshire.
From this entry on Mac Gregory's weblog:
http://www.ahoy.tk-jk.net/Letters/Glasg ... porte.html
You can find the email address of Ms. Emily Malcolm who is curating the exhibit about SS Athenia, and it looks like the sinking will NOT be the sold focus of that.
My thanks to Schiehallion for providing scans of the passenger lists he has available.
The Donaldson Line papers held in the City of Glasgow Archives bear further examination, I am unsure what they hold at present.