Ok gotcha. So you have to make one larger and make one smaller in order to keep the same "footprint" size. I went off a 50/50 pattern that would mean the backside would be 20-30% larger than necessary. Makes sense.
Part of me wonders if it may not be a bad idea to use a piece of wood and my wife's foodsaver to vac mold the front piece of leather and then stitch it to the back piece.
Thanks for the links Jason. I'll take a look at them shortly.