A sagging bumper could only be a rusty or bent bumper iron. They are not very durable so you will do well to get a good one second hand. Why not pm Donalds Alfa (or the other dealer that has joined recently) for the price of a new one?
Second question is harder to answer. Could be residual oil from almost anywhere and the problem could have been long sorted or could be still there. You would need to wipe it all clean and then look to see where it is coming from. Having said that, it is quite normal for engines to have some covering of oil and dirt.
Thanks for that, it did not look like a leak as such just a bit of weeping around the gasket area. The engine was also quite dirty which did not help matters. No mayo on the oil cap and no sign of overheating.
Having just had a look round the "interweb" yes it is the rocker cover gasket apparently this is changed as a matter of course when it has the cambelt service which the vehicle is due anyway so I am not so worried now.