@Sigurd - If its CC licensed as non commercial - the NC bit - then you cant legally sell it on.
@waldronate - I agree that is the situation. My issue with all of this is that the first copyrighted scan should be copyrighting just the new elements of the compilation. If you took the compilation bits away from it that should leave the public domain bit left. Just because I take a photo of a public domain work should not mean that I should be able to copyright the public domain bit in the picture. My photo might be copyright but the image which its of isn't. So if I create a derivative work that strips away my new artistic input on the image - which is practically none whatsoever in the case of a straight up digi photo then I ought to be alright. I dont think you should be able to flatbed scan a public domain image and have any rights at all over that image. Now I know thats not entirely the way it works but that was the intention of copyright in the beginning.
My opinion is that if you choose to meticulously duplicate a public domain work then even if your scanner is expensive or that it took days to do it is not anyone elses concern. The image or shape is still public domain and that goes even if the original was locked away and the duplicator has the only access to it. If he didn't want it published then he shouldn't have published it. Once he has then its a published public domain work which everyone should be able to use.
The current situation is that there is no public domain in any real sense. Every time I take an original public domain work and put a photo of it on the web then my web site image copy is copyright. The only public domain stuff is stuff which I personally have copied from the original. Thats not what the word 'public' means at all - it should be known as 'personal domain'.
Edit -- that wikipedia link is an excellent summary of the state of a derivative work and seems to suggest that the way I think it ought to work is the way is should be implemented in law. I ought to be ok to be able to take a subset of these bestiary images and use them it seems.