One thing you have to be aware of when building off of plans is the accuracy of dimensions between left and right hand parts. I've heard of builders building right and left wing panels only later to find out that one panel is 1/2" longer than the other... So, the moral of the story is to check all the dimensions, don't assume it's correct. Here I've taped together the perimeter frames of both elevator halves so they can be sanded as one ensuring the same sized elevator between left and right.