Not quite what you were asking about, but....
Here are a couple photos of the Brooks saddle I recently recovered. I think you can see that the leather is cut very close to the cantle plate, and skirt cut is patterened on a Unicanitor, and the leather is curved like a unicanitor. What you can't see is that the leather is tapered from full thickness on top to just a couple mm at the edge, even around the back.
Thanks for posting the pics. That's a pretty drastic cut! If the thickness is tapered, I guess they must have removed the leather top, thinned it and re-rivetted it to the frame, yes?
When you say 'recovered', do you mean the frame no longer carries that cover?