The Romance series was published by William C Merrett in 1945-1946. Merrett asked Hamilton if he would try his hand at romance stories so under the pen name of Winston Cardew five stories were published.
Five titles were published. Thanks to Michael Bailey you can read two of them here.
No 1- Peg's Angel 1945
No 2- The Man Who Came Back 1946
No 3- Love Wins at Last 1946
No 4- The Girl from Monte Carlo 1946
No 5- For Love of a Land Girl 1946
William C Merrett also published the Sparshott and the Headland House Series.