How old is the Trooper? I had one 20 years ago or so and it still had rain gutters. If so, they still sell the old Quick 'n Easy gutter towers and they can be adapted to any style bar round, square or Aero (or 2 x 4’s like we used to do the the old days).
I don’t know for sure but fairly old 20-25 years I’d guess.
But as I posted above he’s bought one already. I expect to see it tomorrow. He’s driving here to go kayaking with me.