I'm sorry if this has been answered before, I'm trying to buy some replacement case screws for my MacBook Pro 13" How do I find out what "A" Number my MacBook Pro is?? (i.e A1278 / A1286 etc etc??)
I've never tried them, but they seem to have good reviews.
Edit: just noticed you're in the uk, but if you search amazon.co.uk for "macbook pro screws" you will find something similar... just don't compare prices, or you'll be upset.
If your eyes are better than mine, take a look underneath at the small writing.
Otherwise, find your serial number and follow the instructions here: http://www.everymac.com/ultimate-mac-lookup/