. "class 503" . "British Rail Class 503" . . "EMUs" . "LMS electric trains" . "LMS/BR Wirral & Mersey Class 503" . . . "British Rail Class 503" . "Class 503" . . "Wirral" . . . . "Class 503s" . . . . "LMS Class AM3" . "1956" . "1938" . . "LMS trains" . . . . "LMS electric multiple units" .