you can get the copy from: http://www.dmm.co.jp/dc/book/-/detail/=/cid=b257admmg00019/
You may notice this is the latest drm-free Comic Magnum available, however, this gallery comes from the older version in "dumb" .dmmb format which is not sold by DMM anymore. They tend to remove drm protection from back numbers, but in a bad way that reduce the resolution, meh.