I'm not sure there is any evidence that this particular set of Voynich images was derived from an earlier work. If we start with the assumption that there is some earlier source for these images, then even small overlap in details could be sufficient for identification of this source, I suppose.
As far as I can see, there is not a single clear shape or scene that has a 1:1 correspondence between the VMS images and any other set listed in this thread.
(edit) So, I'm not sure why should we assume that images are derived from some other work.
As far as I can see, there is not a single clear shape or scene that has a 1:1 correspondence between the VMS images and any other set listed in this thread.
(edit) So, I'm not sure why should we assume that images are derived from some other work.