The bonds and/or interest coupons of the drainage district levying the assessment may be lawfully tendered to the trustee of the county in which the land lies by the person desiring to make such payments, and it is the duty of such trustee, to whom tender is made, to receive such bonds or coupons, or both, regardless of the date of maturity of such bonds or coupons, or both; to receive such bonds or coupons, or both, without deduction for maintenance, at par or face value, excluding interest upon past due coupons. Such payment, when so made, shall be as valid and complete a payment as though payment of such assessments had been made in cash. The trustee to whom payment is made may, at the trustee's option, require the commissions due and owing to the trustee by virtue of the trustee's collection of such assessments to be paid in cash instead of by bonds; but, where collection is made by a county trustee, other than by the trustee of the county where the district originates, then only one (1) trustee's fee can be collected and that fee must be paid to the trustee collecting the assessment. In cases where the coupons or bonds, or both, tendered by such person desiring to pay such taxes shall exceed in amount the assessments against such tract of land that the landowner is desirous of paying, the county trustee shall take into possession all of the coupons or bonds, or both, so tendered and, after computing the difference between the balance upon all such coupons or bonds, or both, and the assessment that it is proposed to pay, shall issue to the party paying such assessment a transferable credit memorandum, which credit memorandum may be used by such landowner or such landowner's assigns, in payment of any other drainage assessment due to the district in which payment is made.