Thanks for everyone who offered encouragement.
Not being one to disappoint I am going to give it a go. I loved the greenstuff relief landraider so I'm going to try that myself. I've got myself a landraider crusader box and have already started to convert it.
I wanted to have 2 relief panels like the Scibor one but i thought it would look good if the two panels were either side of the sponsons so i have converted the two sides by cutting off the rivets, and details from the raised panel and cover it with a thin bit of perspex, which i cut a hole in to fit the sponson