USS ROLETTE was AKA-99.AKA in navy-speak is an ATTACK CARGO SHIP, technically a souped-up Auxillery vessel.
The arrangement of letters in navy ship classifications is very important as one letter dropped off or altered would change the "identity" of the ship.(Its like writing MA instead of ME if you were writing a letter to someone in Maine....it just ain't gonna get there.)
PA-31 was the CHATEAU THIERRY---HOWEVER you must understand that about mid war the navy changed the designation of ships in the auxillery-cargo family.PA-31 was a converted civilian liner that did cargo duty in the ATLANTIC before retiring to Hospital Ship duties in NY Harbor BEFORE the war ended.It never saw the Pacific where your diary entires place "PA-31".
It is more likely that he intended to mean APA-31 which was a straight up Attack Transport.This was USS MONROVIA.Just to complicate matters--prior to the redesignation I mentioned--APA-31 had been AP-64....and it did serve in the Pacific.
So to accurately follow the history of that ship you should look for BOTH APA-31 and AP-64.
Dave Berry www.PathfinderHistoricalConsultants.com