Yes, there are some pictures of how to sew an insert with a round top. I'll see if I can find them. I just did some seats for a 71 Roadrunner that had round top inserts. I don't think I explained this very well, you don't double the seam allowance on the insert. The piece the insert is sewed to has it's seam allowance, and the insert has it's seam allowance. If you are using 1/2" seam allowances, the two parts overlap each other by 1". Here is the seat, and the pattern I used to make the seat cover. The line on the top piece is the overlap needed to sew the two parts together which is double the seam allowance, a total of 1".
No one lives forever, the trick is creating something that will.
Last edited by DanTwoLakes; 06-08-2013 at 08:25 AM.