Crew Agreements - SS Batory 1942 - 1945

Trying to complete a family history but have a gap & finding great difficulty in locating Crew Agreements for SS Batory during war years.

National Archives claim to have all records of Crew Agreements between 1940 - 45 how ever they cannot find Agreements for this vessel when I visited Kew.

My mother was a stewardess and after surviving the torpedoing of the ss City of Benares (09/1940) was next found on a Crew Agreement for the mv Britannic (03/1945).

However, once over the trauma of the torpedoing she returned to sea and the ss Britannic Crew Agreement records her previous ship as the ss Batory (after the Benares incident). I can find no records (for war years) of the Crew Agreements for the mv Batory. The ship was returned to Polish owners after the war.

Can anyone suggest where I can continue my search ? Do email me as I only access this site infrequently - email rod.seville@btinternet.com

Grateful for any help