Gary,
The photo seems to show the top of the trim piece - shaped and curved, but not tall enough. It should reach to a fraction above the join of the red & black vinyl. In addition, it wraps around the seat edge - both side and back. It appears to be broken, and the piece across the back of the seat seems to me to be too wide.
This is what it should look like (this is r.h. side)
2 pieces - the vertical one which links into the horizontal piece (you can see where the join is) that goes along the bottom edge and wraps around the front corner of the seat.
Can't you have a look at a local member's car to compare what you've got with what you ought to have?
Martin