If all else fails, you can always cut some slightly larger i-struts. As long as both sides are equal in size, you can't really go wrong...

My bottom wing mounted up straight and true on the first try. It appears as if the top wing is tweaked a little. I will have to work it out when i go to drill the i-struts for the top wing connection. It seems like i have the dihedral pretty close. I just went and checked it out and without any extensive measuring or anything, it looks like everything fits just right. I'll know for sure when i break out the measuring tape tomorrow [&:]