Hiho,
got it ready: The 3-players-board for battlelore!
www.worldofbattlelore.de/index.php
It has the size of an epic board - just for 3 players.
I've seen the original plan of this board at BGG.
All you need is a gaming mat from Hotz Artworks with 2 inches hexes.
You'll need two coregames of BL and maybe two Call to Arms.
And you should create a third type of flags for the third side.