Alternate scan: https://e-hentai.org/g/783286/1e98ec7785/

Really hard to tell which one is better, they're both excellent. I would suspect that they're the same scan, but it's unlikely because it'd be weird for the unleveled, less clean scan to have the cover spread. This one has slightly higher dimensions, and the older one is a bit overcropped on the inside (?) edges.

Base +13, atue +9

http://www.doujinshi.org/book/757843/Admiral!/
http://www.toranoana.jp/mailorder/article/04/0030/26/74/040030267432.html

If the samples on toranoana are closed to "original" book quality.
783286 is the same gray scale, but the picture area is smaller than sample.
This one is the same picture area, but brighter gray scale.

Base +28, zzl4100598 +19