Section 6. The amounts expended by any city or town for veterans' benefits, the names of recipients thereof, the amounts paid to or for each applicant, the reasons for granting him such benefits, the names of the veterans on account of whose services the benefits were granted, the names, if any, of the companies, regiments, stations, organizations or vessels in which they respectively enlisted, or to which they were appointed, and in which they last served, and the relationship of each dependent to the veteran on account of whose service the benefits were granted, and such other details as the commissioner may require, shall, within thirty days following the month in which such expenditures were made, be certified to said commissioner on blank forms provided by him, in a manner approved by him, and under the penalties of perjury, by the veterans' agent and treasurer of such city or town. The commissioner shall examine such certificates, shall allow and endorse thereon such amounts as he finds have been paid and reported in accordance with the provisions of this chapter, and shall transmit the certificates to the comptroller. The commissioner may decide upon the necessity of the amount paid in each case, and may allow any part thereof which he deems proper and lawful. Subject to such decision and allowance, seventy-five per cent of the amounts of veterans' benefits paid to applicants by the cities and towns wherein they reside, but none of the expenses attending the payment of such benefits, shall be paid by the commonwealth to the several cities and towns on or before November tenth in the year after such expenditures.