I have two Brooks saddles that needed new leather, I went to my local saddle shop and bought a piece of thick scrap leather for $3. It was large enough to do at least three saddles. I drilled out the rivets and soaked the old leather in water then pressed it for a couple days until it was dry and used that for a template.
I cut out a new piece and punched out the rivet holes, using the old leather as a guide. I soaked the new leather in water and riveted it to the frame and formed it by hand to the shape as close to the original Brooks as possible. Then I set aside in a warm place and let it dry. When dry the leather will be as stiff as a new Brooks.
I checked out a Tandys before I went to the saddle shop and they wanted an arm and a leg for their leather so if you have a shoe repair or saddle shop nearby check them out. They always have pieces they can't use.
I got rivets from Ace hardware, I did one in steel and one in copper.
Sorry no pics.