Just wanted to note that the leather application in this case is pretty simple. I ended up just using spray adhesive on both the leather and the plywood. The parts are left to sit for about 30-seconds or a minute to tack up, then they are applied. After applying I use a wooden roller to make sure there are no uneven parts (flatten out heavy areas of glue). In my experience it will continue to flatten over time.
Where I'm still debating is the inner door structure. The leather adds a certain compressed thickness to this area so I will cut a recess in the boards to accommodate this thickness, however I'm not sure if I will attach them permanently or build the full panel and attach them with brass wood screws so that the leather can be removed and replaced at some point in the future, leather like this should last a good while, but it's worth planning ahead so that people are encouraged to restore this cabinet in the far future rather than replacing it, or replacing the doors.
Hopefully it stays in my family for many generations and I'm able to dictate restoration processes.
