As soon as practicable after the effective date of the creation of the position of county elections administrator, the officer formerly serving as the voter registrar shall transfer to the administrator all records pertaining to voter registration, and the county officer formerly required to conduct elections shall transfer to the administrator all voting equipment and supplies of which the officer has custody and all records in the officer’s possession that pertain to an uncompleted election. The commissioners court shall determine which records of prior elections are to be transferred to the administrator and which are to remain with the officer.