The 2003 CSSA trial paper solutions are in the mathematics extension 2 resources section here: http://www.boredofstudies.org/view.php?course=3 In the "general" section.
I have a copy of the 2004 CSSA solutions, I might scan and put in resources section at a later date....when I can be bothered! Sorry.
I have finally scanned them and they have been sent, the answer to Q4. a.(iii), a conics question, has been cut-off due to my poor scanning abilities! Sorry!