It's a nice looking truck. Mine is similar. I don't notice a lot of wind noise. But my cockpit is very noisy. I wonder if you might want to do a sound deadening attack on the cockpit? Didn't Doc do one on his and document it pretty well here? I think he was pretty happy with his results. I wired up two headphone jacks to my cockpit stereo. And I use closed headphones which block out ambient noise. I only listen to the headphones when on the open road. I put a switch to shut off the speakers. That way I can listen to what I want to and the people riding can do whatever they want. It works well for me.
Welcome to the forum, great to see another United Specialties.
'03 Freightliner FL112, 295" wheel base, with '03 United Specialties 26' living quarters, single screw, Cat C12 430 h/p 1650 torque, Eaton 10speed , 3.42 rear axle ratio