Starting at the bottom, if you value your face & teeth a full face helmet is your only option. Windscreen? IMO not really needed as the TW will not spend too much time over 45 or 50 mph. Just use tie downs to secure the moto in the truck bed. I use a receiver mounted rack on the back of my tiny Tacoma to haul the bike. However your situation is different. There probably is a way to mount a rack between the truck & trailer, but that is beyond my expertise. The truck bed is probably your best bet. You might find a way to mount the TW on the back of the Airstream. BTW, we have a 42’ 1953 Spartan trailer which fortunately is permanently parked at our winter home in Borrego Springs, CA. Vintage trailer living at its best! Enjoy the TW, it is a great bike for hauling around.