Just another opinion...Since the manufacturer placed the seat tub in the cab, it needs to be there! They installed that tub for a reason, structural or non-structural.
"Pay attention to the details! It ALWAYS pays off."
1949 Chevrolet 3100 Series 1/2 ton Pickup 1964 Chevrolet C10 (Ol' Yella) (SOLD) 1958 Chevrolet Biscayne 2 door (SOLD) 1970 VW Beetle