Colorization - what was it's purpose?

[Jorge_Stolfi]

And, if it is forged, that puts Wilfred back on the table as a possibility.

That is not what I meant.  I meant that the Author may have used vellum and filled the book with drawings only for the artistic pleasure of doing so.  Like many hobbyists would spend a lot of money and time making furniture or pottery for their own use, with no intention of selling it or giving it away..  Like (I think) was the case of that loose "VMS" page that surfaced in Italy and was discussed here a couple months ago.  

All the best, --stolfi