I have the gasket oil leak problem on my 207 1.4 16v petrol engine (56 reg with 40k miles). As I am retired and with plenty of time I thought I would renew the gasket myself and at the same time replace the cambelt/waterpump. So far I have got a quote from a Peugeot dealer of £189 for all the parts including antifreeze and started reading up in my Haynes manual. However, the picture of the cam shaft pulleys on my engine is different to that in the manual and one appears to have a large nut on it and the inscription "lock" near it. Any suggestions?