Thanks to Mike Phillips' answer there I ordered the part for my 1180-1 oven. If you are reasonably comfortable messing around with appliances then this isn't a difficult job replacing it yourself; just make sure that you DISCONNECT THE OVEN FROM THE ELECTRICITY FIRST!
Tip: once you have removed the cover from the oven you will see the old (probably scorched) part. Remove one wire at a time, replacing it immediately with a wire of the same colour from the new part. This way you won't forget which colour wire goes on which electrical connector. There are 2 x white wires and 2 x blue wires (it doesn't seem to matter which of the two wires you use, so long as you get the colour right).
Remember to tuck the fan control back under the cable tie, or (if you've already cut it), put a new one in. Don't use the oven either with it or the cables dangling loose.
I'm not an electrician but I'm reasonably competent with a screwdriver; for me it wasn't a difficult job and I suspect many people would be fine with it as well.
Andrew, November 2010