Behind the seat, You will see the seat back from the trunk.
I get what you are saying but it doesn’t seem to fit right. Could you possibly send me a photo showing up inside where the tire goes? I can’t find any photos online
See picture below pointing to the arrow of the back seat cover piece. The OPGI kits are simply flat pieces of black card board and not exactly like the originals. I have only had the OPGI kit on hand once about 15 years ago and cannot remember the exact orientation of that piece but the short creased end would go under the over the hump fabric. There are basically two ways to put it in, so if it doesn't go in the one way flip it over and trim as needed. The purpose is simply to cover the back top of the seat. Here is the picture:
I am assuming you are referring to the boxed with spare tire mounting stud attached to bottom of the trunk hinge box pointed to by red arrow, and not the trunk hinge itself. As noted on our Trunk Compartment help page (Click Here):
"NOTE The 1963 Coupes, and 1964 Coupes and 4 window Sedans had the spare mounted up on the hump below the rear package tray. Other body styles had the spare tire mounted in the floor pan via a J hook, large black painted metal pan and large wing nut. "
This means that all the other 1963 & 1964 body styles (most) do not have this spare tire mounting box, as the spares mount on the trunk floor. What you will find instead is a box bracket protruding from the floor pan as seen in picture below, when a long J bolt and wing nut are used to secure spare to floor instead of the box and j bolt as seen in your picture.