I'd say your second quess is right Christian. It's an unusually patterned Morelia s. mcdowelli. A nice striped specimen. Good one Dave.
Pics are a bit too small though Dave. Try around 600 X 400 pixels.
that's a very good looking coastal you have there one of my hatchie's has a stripe like that but it dosnt start at the head like that congrat's mate thats a very good looking coastal you should be proud