(a) A will that cannot be produced in court must be proved in the same manner as provided in Section 256.153 for an attested will or Section 256.154 for a holographic will, as applicable. The same amount and character of testimony is required to prove the will not produced in court as is required to prove a will produced in court.
(b) In addition to the proof required by Subsection (a):
(1) the cause of the nonproduction of a will not produced in court must be proved, which must be sufficient to satisfy the court that the will cannot by any reasonable diligence be produced; and
(2) the contents of the will must be substantially proved by the testimony of a credible witness who has read either the original or a copy of the will, has heard the will read, or can identify a copy of the will.