That's a good thought on going industrial for heavy leather, but based on what you're describing for those collars, I'm a bit hesitant on the LU-563 being ideal. It's a walking foot machine which is key for leather, but it's really designed more for medium to heavy upholstery, canvas, and lighter leathers. I think you'll likely be limited on thread size to something like 207 or maybe 277 if you're lucky. I suggest you look into a triple feed / compound feed machine for the kind of heavy-duty leather work your dad has. Those are built to really grab and pull the thickest assemblies and handle bigger threads with ease.