Calling all Mantetsu Owners:   I'm doing a very informal survey of serial numbers on Mantetsu blades. I'd like to see if there is a progression of the katakana from year to year, or if they are randomly scattered throughout the years. If you own one, please post the year and serial number below. I seem to recall a woman on this forum that had collected one from each year of production! If you read this PLEASE post your dates and numbers.   Thanks to all who help out!   Mine: Spring 1