Trev,
I'll show you what I used to create the backround...
The image below is a screen grab from Mission 3 of the game. (Although I'm on Chapter 5, it's still only mission 3 of the game). I cut out the cargo cannisters and then added the nebula image behind them. I then added a starfield behind that. I used the Colour Balance tool to alter the nebula colour to a more bluish tone and set the layer opacity to about 40% so that you could see the stars through it.
I then added a new layer set to "Screen" and just airbrushed the sun into the image to emulate the original. Finally I added the Falcon, which is one of many images taken of my son's Falcon, that lives in their...(eherm, our), playroom...