Section 85D. 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 for incapacity shall apply to call members of its fire department, except that the pension of any call member retired hereunder shall be the same as that of a permanent member of the first grade of the fire department, or, if there be no grades, the same as that of a permanent member of the fire department performing duties like those which he performed.