Very happy with your designs, #16 is my favourite, but definitely needs a distinguishing feature of some kind.
Could I get you to use an icon which reminds the viewer of the Sydney Opera House - if you used this and put it above the top blue line, I reckon it would work well.
Give it a shot and see how we go, cheers mate can't wait to see your update !
#70 and #72 are looking incredible mate, the only change I'd make would be to use more subtlety in the opera house image. The current idea looks like something out of transformers or pokemon, give it a shot with something a little more simple, for example the top two thirds of the image below: