Hi Peter, unfortunately I have never seen the book, but I just thought it strange there is so little information available compared to almost every other species. The one in this sites species description is the only one I have seen. Its hard to tell if the photo shows the species in its normal coloration or if stressed hence paler than usual colours, a broader set of photos for ID would certainly help I think.
It would seem that this species really is under represented by breeders so if by chance someone came across them somewhere, then having the tools available to propely Id would be of great help.
I might have to buy that book at some point though!
Regards