In case of the death, resignation, removal or other disability of any county collector, during the time the tax books are in his hands, and before the time specified for making settlements, the county clerk shall demand and take charge of the tax books. Said clerk shall appoint one competent person, the legal representatives of the collector may choose a second, and the sureties of the collector may choose a third, and the persons so appointed and chosen shall examine said tax books, and it shall be their duty to ascertain the amount remaining uncollected, and make out a correct abstract of the same. If the representatives or sureties of such collector shall fail or refuse to choose persons to make such examination, then the person appointed by the county clerk shall proceed to make the same and report the same to the county clerk; provided, that should there be but a small portion of the taxes collected at the time of the death of the collector, then the amount actually collected shall be ascertained and the same books used in completing the collections.