Looks like ya already got some good info.
I wanted to add this odd fact to the collection.
The manufactures went cheap on the boards they used what I think was called finger joints some of the boards. Even on the seats. Dang I bet that would pinch ya something awful!
I will replace the original wood on mine one day. I will recess the carriage bolts and try to duplicate all dimensions as close as possible, but no but pinching finger joints.
http://i561.photobucket.com/albums/s...lood/003-1.jpg
http://i561.photobucket.com/albums/s...lood/002-1.jpg
good luck with your project