[Yaesu] FT1000D Serial numbers

[Hardy Landskov]

All,
My technical supplament has a section in it that shows the mods that have
been made to the radio over the production lifetime. It will say something
to the effect  "Units with serial numbers XX0040000 and before require
field modification." I have serial number 4E360027 which does not align
itself with the format in the book being one digit shorter.
Does anyone know how to decode these serial numbers as to what year mine
was made?
Thanks
Hardy N7RT