There is a Facebook group named "LIBERTY SHIPS! US Merchant Marine in WWII 1939-45 (https://www.facebook.com/groups/1416936411761154). It is a public group that you can easily join if you have a Facebook account. Photographs of Liberty ships (SS WILLIAM D PENDER was a Liberty) are often posted to the group. I suggest you make an inquiry there. Good luck.
Ron Carlson, Webmaster Armed Guard / Merchant Marine website www.armed-guard.com