The mean phase of the carrier is solid for hours, suggesting the transmission is at least Rb controlled as the points do not rotate around the vectorscope screen. 

The interesting bit is the smaller circle with a radius of about 15 - 25% of the mean signal amplitude, caused, I assume, by ionospheric frequency shifting of a substantial skywave portion of the signal.     The plot represents 8.2 seconds worth of carrier history,  the small circle taking about 4 seconds to form, suggesting there is 0.25Hz worth of skywave frequency shift associated with it.

I'll try Droitwich as dusk arrives, but its annoying carrier modulation means the resulting plot will not be so 'clean'

Andy  G4JNT