I don't know if its been said before but having just bought the DVD
of series 1,2,3 and 4 I found an episode with Sue Lloyd in it. I
haven't made a note of which series or number it is but I'll find
out, and maybe get an image or two later.

She plays a very posh lady who just loves "Dorgs"

Also I know its a bit late but BBC2 had a clip of Ronald in Dr Who on
its series that looked back at the tv listings from a year. What we
watched I think the show was called!