Hi Adrian,
I will be more than happy to assist you if I can. Do you have any other information on your Father ? Is he still living ? Do you have any information on any Aunt's or Uncle's (your Fathers brothers and/or sisters). Somethimes you have to find a brother or sister to find the grandparnets.
I have information on only one Frederich Curt, born about 1877, this might be your Grandfather and then again it may not. His brothers are listed along with his parnets, Edward and Susannah Curt. His age would fit the time frame for your Fathers birth in 1915. This Frederich's brothers are listed as: William, Charles, Edward, George, Thomas, Joseph, and Henry. No sisters are listed.
You may post a reply here or you may email me directly if you wish. Looking forward to talking to you, Nina BrtMoon96@aol.com