This is not really modern in terms of construction or design, but what makes it unique are the materials. It has a glacier spruce top. The spruce was recovered in a glacier and hence is very old — 3000 years. It has a unique color due to the minerals that have penetrated the wood. The back and sides are also unique as it comes from “The Tree.” It’s a highly figured, quilted mahogany that came from a felled tree many years ago and was recovered.
Slash owns this acoustic guitar now. You can read more about it here.