(a) If, after an assessment is made under this chapter, the amount assessed and apportioned is insufficient to defray all the costs of an improvement:
(1) the governing body may assess the deficiency against property specially benefited and the owners of the property and apportion the deficiency among them, after notice and hearing as provided by this chapter and after complying with each provision of this chapter applicable to original assessments; or
(2) a deficiency assessment may be made after notice and hearing before the commission in the manner provided by Section 314.047.
(b) A municipality may issue assignable certificates evidencing the deficiency assessment.