...and I thought I might have found the source at
http://www.flickr.com/photos/2319380...57605039166300 , where this one may also be found; it, however, contains only 25, doesn't include the saucier below-decks ones, and has a lower top picture size than these. Further, the user's whole photostream is these 25, and since there clearly were more as Osreb's post shows, he can't be the originator. As consolation, there are several other (though smaller) pictures not in the previous post: two steps forward and only one back?