Anything in this chapter to the contrary notwithstanding, those persons who were members of the retirement system on January 1, 1973, and who (1) were transferred under loan from an employer to a federal agency during World War II; (2) during the period of the loan, were selected by the United States government from official registers of the State Merit System of Personnel Administration, paid according to state salary schedules, but were ruled ineligible for federal civil service retirement membership; (3) were transferred from an employer to a federal agency, but whose work was continued under the supervision and control of the employer; or (4) resigned or took a leave of absence from an employer to accept overseas service with the American Red Cross or other Red Cross organization during World War II and who were subsequently rehired or reinstated by an employer shall be entitled to service credit for periods during which they were so employed.