I went back tonight and took your advice about walking around. I quickly discovered a problem with any angle changes; background lights, and trees. To the tanks right, behind and in front of there are a lot of lights and neon signs. Which really messes up the shot. The tanks left side is the only side that's unaffected (that's facing towards the park.)
I've thought about photoshopping as many of the lights and signs out as I can, but ... well I'm lazy. lol
Maybe another time of day might prove to be a more worthwhile venture? I've not given up yet!
Thanks for your help pinball.