Hi fellas, I want to apologize for replying so late to some of posted questions.
For chipping I used two different methods and two different paints. First of all I mixed a darker steel paint + a slightly greyish steel colour from Revell Aqua Color range. Then I took a smaller brush and marked/painted all edges that could be or are/were in contact with the crew (footsteps or similar) or influenced by the dry desert environment. After that, a piece of simple cleaning sponge was used to apply very tiny chipping marks, using the same dark colour. For both techniques I used the dark steel colour. Then, I took a new and fresh piece of cleaning sponge to apply the slightly greyish steel colour, as I did in the 2nd step. For the finish I used rust pigments.
Fuel lines were made easily by using 0.4mm brass wire and small parts of isolation from an old unused cable (Hi-fi or similar). You just have to peel of the isolation carefully from the old cable and cut it into short pieces. Automatically you have a connector with a hole. Now all you have to do is put the wire through and you're done. Fix it with superglue.