It is finished!
And I'm really happy about how it turned out.
I tried to keep the trunk "as-is" as much as possible, minus the stinky wall paper, so after sanding the interior, I applied a MinWax penetrating oil stain in "natural" that revives the wood and maintain its true color. There are many knotholes which makes the wood inferior and is why I think these trunks were wallpapered. As I took the trunk apart, I noticed there was tape across the seams and over the knotholes to smooth it over for wallpaper. I like the character and imperfection of knotholes, but they are a little rough and rustic. The musty-trunk smell is now gone, but it has acquired the smell of the stain which is fine with me.
On the exterior of the trunk, I rubbed some natural stain over the wood and oiled the steel exterior and leather with Nor-V-Gen oil -- a boot oil we use on our boots. It helped to shine up the metal and removed dirt and gunk that was there and it deepened the color of the leather. There is a blue-gray tinge to the outer wood slats that I wanted to preserve and of course, all the bumps and dings and scratches remain -- the trunk earned them. I haven't decided what I will store in it yet, but I have moved it to the living room as a side table for the big leather chair. I think it looks smart and brings a lot of character to the room.