If you read the N9 service manual

http://mynokiablog.com/wp-content/up..._L1L2_v1.0.pdf

It suggests that both IP4 and IP5 screws are used, but the ones that everyone strips the heads off are the IP4 ones.

Base on the P&P costs of the previous link I posted I purchased both tools.

I am down in Hampshire if it's any help to you...

-Nic