Design Context Cover Design & Spine Width

Having finished the design of the inner pages / spreads I wanting to get my context book completely  finished so I set about designing the final thing - the cover. Yet to print the inner pages and having a print slot book this afternoon (my last chance to print apart from drop-in) I thought it a good idea to print my cover in the slot. Having not printed the inside pages I thought  it would be a good idea to make the inside stock choice and dummy up the number of pages to get an accurate spine width prior to printing the pages. I chose bulky newsprint and made a mini 60 page french fold book to get the measurement - 9mm.

Armed with this information I could design the cover. With plenty of other things to be completing I didn't want to spent too long on the cover so I elected to use the design form the diagram used inside the book (minus information).

Too boring / standard:

 Better - like the cross spine artwork.

 Not working in a column but the overlay is working nicely:

The winner - enlarged illustration + overlay off of the left & right edge. I like the wave motion caused by the lines of the overlapping illustrations: