Technical Rear seat doubt

[lfp]

Dear friends,
I have some doubts regarding my 1958 Fiat 600 from the back of the rear seat.
Please find bellow manual photo and from my car too (where I have some side brackets), can someone post photos from the same serie?

 

[summersc]

Here is what mine looks like. I would expect to see the pivots for the seat back in that location. Here is the pic of the pivot mount in my car:

And here is what the seat back looks like snapped into place:

and finally, with the seat back installed:

My car has been modified a bunch, but the rear seat back mounts are stock. Sorry for the slow response... i am just now getting around to installing my backseat. I hope that helps!