Barnes and Noble books are not leatherbound though they advertise as such. They use bonded leather, which, though it sounds similar, is really low quality, closer to paper boards. That's why they can sell the things for $20. Modern leatherbound books would be along the lines of Easton Press...
It's hard to say whether she was going to finish it or not, because she didn't really plan to die at 56. Also, you have to remember that even though it was at volume 137 or so, that's just because Kurimoto was much more prolific than Miura. If I recall correctly, she died during the 30th year...
In terms of comics, "Absolute Sandman" comes to mind. As a special edition, the Berserk work here clearly hasn't been given the full amount of love it deserves. However, the size and overall design are just right. I'd have preferred real leather, but only niche publishers work with that...
Here are a couple I don't think I've seen posted here.
https://www.youtube.com/watch?v=6vVEOMpOV-k
https://www.youtube.com/watch?v=nRuOhaUU9Js
Tale of Berserk and Viva la Vida as posted above are probably my favourites, but this last one here, "The Door Has Been Opened", is really, really good.