Any veteran who served in time of war, if he is not eligible for disability compensation or pension from the United States through the United States Department of Veterans Affairs and if he has attained at least the minimum earned rating on any examination held for the purpose of establishing an employment list for original appointment shall have five points added to his earned rating. Any such veteran, if he is eligible for such disability compensation or pension and if he has attained at least the minimum earned rating on any such examination, shall have ten points added to his earned rating. Names of veterans shall be placed on the list of eligibles in the order of such augmented rating. Credits shall be based upon examinations with a possible rating of one hundred points. No such points shall be added to any earned rating in any civil service or merit examination except as provided in this section, the provisions of any municipal charter or special act notwithstanding.