沒查到你說得這個，不過有股購到這個：

http://www.missingassets.com/postal_money_order.htm
覺得你還是去郵局問1下先，

search for "money order" in this article,
"For a small fee, you can obtain a copy of a paid money order up to 2 years after the date that it is paid."
http://www.pueblo.gsa.gov/cic_text/misc/postal/benefiting_consumer.htm