Sounds like a good endeavor. I will mention that there are many Sengoku players that would absolutely bang down your door to get that map. I would suggest you mentioning it to them.
There are a few Sengoku forums out there just Google them. As for printing them out, I personally wouldn't do that as there are so many Virtual Tabletop programs out there that could use a map like that. If you can try to refrain from putting a grid in. A grid should be able to be added by the user and since different systems use different grid types and sizes putting in a grid would reduce its usability.