hgger69,
If you must replace your trunk pan due to rust, hang onto the original pan and check it carefully for where the original spare tire hold-down loop was welded to the pan. There may be some dimples in the new sheet metal pan to help locate the loop back in its original location. If you are not able to do this, others on this site with original unrestored cars can measure from some designated datum points in the trunk pan, exactly where to locate the loop. This will be important to properly locate a full size spare tire.
Also, if the trunk pan is replaced, remember to transfer to the new panel the fuel sending unit wire clip (see picture), spot welded to the exterior side of the hump, just inside the flip-down license plate fuel door, on the passenger side.
AMP Products has NOS and/or very good reproduction hardware, including the J-Bolt #B-11673 (about $8) and Wing Nut #B-10612 (about $6). Check them out at
www.ampproducts.com.
Good luck with your project!