I posted a couple of pics of mine in bits in my project thread. Not sure what you mean by not taking into account inertia reel belts?
Some of the manual directions are not that easy to follow IMHO. With the seat out take off the alloy covers, locate the the hex nut on one end of the torsion bar. If the problem is the seat doesnt lock in place, you might be able to improve that at the nut - remove the small screw that prevents the nut from turning, turn the nut a couple of flats (1/6 turn each flat), refit the little screw, check operation.