Super rare Original Polzel Paddle Saddles.
There are a few photos of them in action on the web.
Had plans to try these out but never came to fruition and have been carrying them for two moves so time to let them go.
Each seat separates from the cross bars.
These are located in College Station, TX so it more probable that they will have to be shipped. Asking $500.
I can get more photos or measurements if you need.