I am still suffering from that horrendous interference and am no nearer tracking down its source.
I have made another video showing the effects. As I mentioned before the signal seems to build in intensity and tends to drift frequency and then fade away. I know the FUNCube dongle filtering can be susceptible to out of band signals and images especially in the VHF but the video shows the same interference on a normal receiver with a different antenna.
Interestingly I have monitored a few local amateurs also mentioning problems with noise that has been affecting them, one even described an "annoying pulsing sound"