This Article shall not operate to deprive any participant of eligibility for an annuity or to reduce the annuity to which a participant would have been entitled under the provisions of "The 1941 Act," in effect on June 30, 1955, if prior to June 30, 1955, the participant had met the minimum requirements for an annuity, or was employed by an employer on that date.
40 ILCS 5/15-137