Thanks for all your comments! The leaves are just copper sheet, leaves cut out and edges sanded. Then I draw in light vein lines on the "back" of the leaf. I lay the leaf on a piece of soft wood (cedar scrap) and I use a big washer then, about 1 1/2 inch, and roll it along the vein lines and tap with a hammer. The leaves begin to roll and curve inward into a leaf shape and you just keep tapping until you get a desired look. Wash off any of the drawn vein lines with mineral spirits.
Phil you're welcome to copy. I saw the plans for this in a gate magazine or website back in 2003. I built a narrow one to just stand as a decoration near a mailbox then. This one was from memory and made wider to fit as a replacement gate.
Thanks again,
Tom