I also have all 3 modules 2morrow, WJEC, and in my fairly brief revision periods I "think" there are;
common law rules;
literal
golden
mischief
modern purposive approach
stat. rules;
interpretation act 1978
Stat. objective
and definition sections ie, the theft act 1968
And about the aids to stat. interp;
internal - the statute itself, Edjusdem Generis, etc
external - human rights act, law reports..
Hope thats some help, although this is off the top of my head..