I'm sorry, but I don't know anymore how long I worked on that quilt, I never write it down... but I think about 500-600 hours.
The quilt is seamed horizontally, the center is a complete width of fabric (44") and two halves of the second width are placed on the top and the botton. I will never do it again like this, it looks better when the seams are vertical (one complete length in the middle).