Whilst looking under the car (and being dismayed by the sheer rust under there) I noticed that there is a very minor but wet oil leak around the seal where the gearbox selector rod enters the gearbox case. Haynes says that this seal is replaceable with little effort. Can someone please tell me where one may be obtained from and hopefully it's part number. I looked on eBay but nothing concrete, and am reluctant to go to a Ford dealer as the prices are always frightening.

Success - I found the required parts on eBay for £13.98 all in - the boot and the shaft seal. Next fine day I'll have a go at fitting them. BTW gear oil 75W90 is now around £11 a litre! The box takes 2.8 litres - expensive eh?

Assembled all of the kit - got the car up on ramps - slid underneath and wiped over the boot only to find that nothing is wrong! The boot is intact and the shaft is clean. The boot is not full of oil and just covered in dirt that looked like a leak from a distance. To be sure, removed the oil filler plug and checked and the box is full of very clean looking oil. Relieved in one way that I haven't got overheated ground up gears and bearings but disappointed in another that if I hadn't looked under the car for the radiator drain plug I wouldn't have been panicked into action.