For the doubled bottom hem, the decorator chose to leave the selvedge on to prevent fraying.
After some trial and error, I found that the best way to control the top was to sew the translucent buckram before making the double fold. This worked beautifully since there was a line to follow.
Again, trial and error proved that you should NOT use straight pins to secure the header for pleating!- they get caught all over the place. Safety pins were the answer.