With the covers taken apart, I can better see what I'm dealing with. The bottom cover took longer to take apart because there are more seams. I also marked the bottom cover a lot more than the back cover because there are a lot more corners. As far as the unlettered marks in the center of the seat are concerned, that was Bob showing me where I needed to mark the cover. When I told him that I wasn't going to put any vinyl down the center, he replied, "Oh - then forget those."
This is the bottom cover - the first one I cut apart. It looks a lot simpler in pieces than when it was all sewn together. I'll try to remember that when I'm sewing the new one together. The entire cover consists of the front boxing, the insert, and the tail. Not shown is the J channel that I'd already cut off of the tail. That J-channel is the piece that slips over the rear rail on the seat frame. I made the mistake of cutting the boxing apart at the center seam, forgetting that I was going to try to make that boxing out of one piece. According to my math, I'll have enough vinyl to make the panel, with 10 inches to spare.
Picture 1: The seat bottom insert. Not seen in this picture (it was added after the picture was taken) is an arrow drawn down the center of the seat, running from back to front. The reason for the arrow will become obvious later, but it has to do with orienting the fabric I chose for the insert.
Picture 2: The tail (top of picture) and the two halves of the front boxing. The J-channel gets sewn to the edge of the tail that's not index marked. I'll either sew the two halves of the boxing back together to make my pattern piece, or just pin it back together.
Picture 3: With a cover that's this wrinkled, I'll need to press it flat so I can use it for an accurate pattern. No big deal - DanTwoLakes did a tutorial on doing just this very thing. Look for it in the Interior Forum.