Hey Ian, I'm getting one made - my sister (an artist) will hand paint it onto the sheet for me. No hassle doing two at the same time. My mate will give me the polycarbonate sheets for this - crystal clear stuff.

What would be handy if you or someone else has the exact dimensions for the sheet, and the outer point dimension / circumference of the web itself, and distance from each edge.

Happy to scan mine and forward on, will also give measurements.  I'm off to Melb for a week with work, so there will be a delay.  PM me your email if you want me to do it.