I'm not sure if you are using WinCC flexible or TIA Portal, but at least in WinCC flexible (2008) there's an option in properties - general called "Dial graphic", where you can set a custom picture for the gauge circle. Now all you need to do is play a bit with MS Paint or something like that.
Hope this helps.
I don't see why people would still care about travelling salesman problem nowadays. You can simply buy stuff on the internet.