If, upon the completion of the improvement project, it is found that the assessment previously levied upon any property is more than sufficient to pay the costs of such improvements, then the council must ascertain and declare the same by ordinance, and when so declare, the excess amounts must be entered on the lien docket as a credit upon the appropriate assessment. In the event that any assessment has been paid, the person who paid the same, or his legal representative, shall be entitled to the repayment of such rebate credit, or the portion thereof, which exceeds the amount unpaid on the original assessment. (Ord. 1085 § 14, 1958)