(a) Except as stated herein, no contract for a reversionary annuity shall be delivered or issued for delivery in this state unless it contains in substance each of the following provisions:
(1) Any such reversionary annuity contract shall contain the provisions specified in sections eighteen, nineteen, twenty, twenty-one and twenty-two of this article, except that under said section eighteen the insurer may at its option provide for an equitable reduction of the amount of the annuity payments in settlement of an overdue or deferred payment in lieu of providing for deduction of such payments from an amount payable upon settlement under the contract.