Originally Posted by fatbat
for patches, just pull the cordua outer layer up and away from the tarp inner, and sew away. A curved upholstery needle is best.
+1
This is what I did, with a little care you don't need a curved needle. I used a 1 less car patch, and put some machine "hemming" stitching (I'm sure there is a proper term for this) around it to stop the fraying before I attached it.