LesB, yes, I could have left them unfinished, and yes, the reason I finished the exterior was for my aesthetics.  Also, the boxes are on the edge of a wooded area (facing a grassy area), which I needed to do to in order to abide by my condo rules.  And I've seen many bluebirds on the edge of this wooded/grassy area, and a few have checked out my boxes.  So, I'm hopeful that they'll nest there eventually.  

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