Section 85A. In any town which accepted this section prior to January first, nineteen hundred and forty-six, the provisions of section eighty-five or section eighty-five E, whichever is in force therein, relative to the retirement of permanent members of the fire department and police department for incapacity shall apply to call members of its fire department and to police officers appointed under section ninety-six of chapter forty-one, except that a person retired hereunder shall annually receive from the town a pension at such rate, not exceeding five hundred dollars a year, as the town may authorize.