I guess you missed reading this.
Re-drawing only a fourth of it took me 5 or 6 hours.
This is mostly caused by the fact that autoCAD is a vector software, so it doesn't do well drawing out hand sketchs.
You can use GIMP to do the statues/rocks/trees/etc, but you'll still need to convert if from a raster image to vectors... which may not convert cleanly
I have made a few half hearted attempts using ACAD with other Maps using ACAD.
Nice work; well done.
Don't sell it; as the copyright cops will be all over you.
As long as you only have it for your own use (even in a campaign), I think no one is going to bother you.
Of course if you create original maps and not copy old copyrighted ones, those are a totally different story.
I have created maps using ACAD, intending to use them for adventures I wrote.