The Xanadu quilt looks similar to the original one posted, but the original one does not appear to have any seams in the large blocks. The Xanadu quilt appears to be 2 2-1/2*4-1/2" blocks pieced together to create the illusion of being one single 4" finished block. This could easily be done by cutting a jelly roll into pieces.
The other possibility for the original quilt is that it was done using English Paper Piecing with 2" and 4" paper squares. Since the original quilt does not seem to have more than one solid piece creating the large block, I would bet that it was made using EPP.