(a) If the original Disbursement Postal Money Order is received or recovered by the owner after he has requested the Postal Service to stop payment on the original but before a substitute has been received, he should immediately advise the Money Order Division and hold such original Disbursement Postal Money Order until receipt of instructions with respect to its negotiability.

(b) If the original Disbursement Postal Money Order is received by the owner after a substitute has been received by him, the original shall not be cashed, but shall be immediately forwarded to the Money Order Division. Under no circumstances shall both the original and substitute be cashed.