MH 270, a 777-200ER, registration 9M-MRO, construction number 28420, line number 404, was built in 2002 and delivered to Malaysian on May 31, 2002
Based on the below link from Boeing's official website, 9M-MRO flaperons were manufactured in Spain by Constructionnes Aeronauticas SA(CASA), which has been owned by EADS since 1999, now called Airbus Industrie NV. A bit ironic.
Please read the below link carefully(before you tell me that 9M-MRO was not a 777-300ER)
Design 90 Percent Complete on Long-Range Boeing 777-300ER - Jun 11, 2002