As I said in your other thread, this doesn't strike me as a good idea.
http://www.internettablettalk.com/fo...9590#post99590

But if someone really wants to try, I think the first problem will be that the Flasher will see the OS2007 firmware image is written for RX-34 (N800) hardware and the N810 hardware identifies as RX-44. Flasher won't let the install proceed.... for your own protection.

Probably the only way to get it on there will be using a method similar to the way OS2008 was installed on the N800:
http://www.internettablettalk.com/fo...4459#post94459