Thanks Dan! the Kenmore truss sheds a lot of light for me on the historical "why" part. It is also becoming more apparent to me as I study buildings that aesthetics played a much greater role in the design and joinery decisions than we give it credit for.
The "artistic liberties" at FF Pavilion follow in this tradition. If I understand you correctly, the joint decision was not based purely on structural or historical value alone but was chosen for its visual effect as well and still performs its duty well in this particular structure with all loads taken into account. It perhaps even sheds a little insight on the personality of it's architects and/or builders.
I am guessing that this is perhaps the answer to my Rindge issues as well. The architect decided that some compromises could be made in order to achieve the desired visual effect. He stretched the rules a little but still kept the structure sound by over building other areas.
Perhaps my next visit to Fredericksburg I will stop at Kenmore for a look-see. I will also be watching for the next raising.
Thanks again!