This is neat. Nice job printing, too! I might be tempted to crop the top down to just above that heavy, horizontal line to focus the viewer to the cool patterns.
I really like the image, and I think this has real potential to become great. Personally I would print it about 1 1/2 stops darker and increase the contrast by a few grades as well. I would then crop the top 1/3 off to strengthen the design. I have seen very similar work by Minor White
If you would like I will post my 'vision' on the web for a few days so that you can see how I would print it.
Thanks Phill, I look forward to that. The actual print is more contrasty and darker. This is one of those images that I keep revisiting, great to get some feedback on it.