The Department of Military Affairs of the Commonwealth shall select, procure, award, and provide for the furnishing, at request of the veteran, of a service medal at cost to all honorably discharged veterans of the World War who were residents of Pennsylvania at the time of their entry into the service: Provided, That the proof of such service shall be based upon decisions made in connection with the payment of Pennsylvania veterans compensation: And provided further, That such medals shall not be issued to officers and enlisted men who were commissioned or enrolled in the Pennsylvania National Guard, on or prior to, August fifth, one thousand nine hundred and seventeen, and who have received the medal provided for that class of personnel. The detailed specifications and design shall be selected by the Department of Military Affairs.