That is a standard way of dating a sword. Nothing really special about it.
Sorry, but the signature is way beyond my meager abilities of translation.
I suggest you post the inquiry on the Nihonto Message Board at:
http://www.militaria.co.za/nmb/index.php
There are a lot of very knowledgeable folks on that board, many from Japan, who I'm sure can help you. Sorry for my limited knowledge and ability :-(
Rich S