Just a comment/question on the Kirkey's being "floppy".
I have the newer 65 Series seats. These are a 2-piece with a seat & back that is bolted together and adjustable for height. Kirkey has also added a formed angle/corner braces that wrap from the side to the back. I don't believe that this was part of the earlier 47 Series seats.
I do know that Kirkey recommends the back brace and will fabricate and install something but have yet to understand where the seats are lacking support or strength.
Insight appreciated.
Jim