If he is sending you an Postal Money Order, wait till you get the M.O., then ship him the parts, that way you wont loose out. You can deposit the M.O. anytime to your account. M.Os. are safe.
Dave
I send money orders in US funds, safe and secure, cash the money order send the parts. In some state if the seller tries to screw the guy who sent the money order that constitutes mail fraud.
