Factory Seats ?

According to the 2012 Toyota Brochure Information, the seats on the SR5, Off-Road, and Sport are defined as;

Sport fabric-trimmed front seats; 4-way adjustable driver’s seat with power lumbar support; 4-way adjustable front passenger seat (with fold-flat capability on Double Cab)

The differences are;

A. SR5 fabric-trimmed seating surfaces (SR5), or;
B. Sport Water-Resistant Seats-trimmed front seats (Off Road - Sport)

Questions:

A. Are the Front Seat Structure/Frame the same in the SR5, Off-Road, and Sport with the only difference being the Fabric Trim?

B. Are the Rear Seats in all (SR5, Off-Road, Sport) the same Structure/Frame and Fabric?

I have read many posts here about the seats but everyone has a bias toward their own so I have been unable to deduct the facts about the seats.

Any help is appreciated.

 

Thinking back to 2006, the TRD models had structurally better seats than SR5, but the fabric on them was a little different. Not sure about today.