Enemy brothers

by Constance Savery Author

(From Google Books): A 12-year-old German boy, Max Eckermann, is taken to England against his will by patriots fleeing occupied Norway. An English airman, Dymory Ingleford, identifies Max as his brother Tony, who was kidnapped as a toddler by a childless German woman. Placed with Dym's family, Max's stubborn loyalty to his German citizenship pits him against his loving, but unsympathetic hosts.