about polishing them up: Didn't appreciate that they were anodised.

if they are, then you're SOOL unless you go through the hassle of deanodising them with caustic soda and then emery paper all over and then 30 minutes with a buffing wheel and rouge. that's too much hassle for soemone who does not have a polishing wheel handy though.

see here for a quick guide to polishing bike alu.
http://www.raydobbins.com/polishing/
so that you end up with cranks like this:

as long as the teeth get a bit better degreased and cleaned, and the photograph is taken so that the reflected shine does not highlight the heel scuff marks on the cranks, you should be OK.
try to go with a bit more of a general clean and a light polish with a metal polish, even something like Brasso, and a rag.