110CSW second row seat mounts

I’m at the point where I need to start thinking about the mounting of the second row seats. I have all the brackets that mount on the second row upstand, but I can’t remember if these bolted through or into any steel behind the second row upstand. Does anyone know? I’m concerned that there should be something behind, to take the loads associated with the seats, maybe a load spreading plate or chassis mount?

Edit: it’s a 200tdi with 3 single seats.