David if you know of a place in your area that re-upholsters furniture, you can often get scraps from them for cheap or sometimes free depending on how much you want. Granted it helps to have done business with them before but not a necessity.
I scrounge leather pieces from various sources. I cut it out of old backpacks, belts, gun holsters, furniture, sal val jackets and used welding aprons. Every once in a while you can find a good sale on new welding aprons at a discount tool store that I won't mention by name but most folks are familiar with.
Next year you should try to tan a deer hide. They are pretty easy to obtain during the season. I did my first this last winter. It's a lot of work, but worth it I would say. The more parts of the animal I put to use, the more peace I can find from having taken it's life, which is not something I take lightly.