Cool, that sounds like a good start. as for dust inside your graphics card (aka between the cooler enclosure and the PCB itself), I think there'll almost always be dust there, the amount will depend on how dusty you let your computer get, but usually it doesn't affect cooling too much unless you literally have a blanket of dust in there or something
If you haven't done this already, try running your system with the case open, pay close attention to your fans and make sure they all spin up.
My Graphics Card is now about 30 degrees celsius lower!
It is now 50 degrees celsius when IDLE!
Then when I play, it is about 65 degrees celsius!
I cleaned the inside of my graphics card and it worked!