Help me ID these parts

[Oldmopars]

I got an AMT Fruehauf trailer kit recently. When I opened the kit there were some parts from another kit, they don’t go to the trailer. 
It looks like a tow hitch, seat harness and a duct of some sort for a race car carburetor. There is also possibility a roll pan?

Any idea what kit they are from?

 

[Can-Con]

AMT '65 Fairlane 

[Oldmopars]

Thank you, you are right, but it’s strange it is only part of the tree. 
I guess it goes in the parts box.