Before I started the UP 14t trucks, I designed some seats for the Wiseman C&S #20 kit I was building. I had them printed as part of my order for the truck test prints.
I attached the arm rests to both ends so they could stand on their own.
Yes, I could do that. I might have to beef up the arm rest supports, as 2 of them snapped when I removed them from the sprues, and a third lost half of the support.