Another frequent receiver is Phil, VK7JJ, who gets amazing WSPR reception reports. The trick, of course, is low noise reception. I'm doing pretty well for a suburban block. Phil is on a property in Tasmania and has taken considerable steps to reduce noise.
Ross, VK1UN, makes a good point that with this much attenuation it might be that signal leakage is actually being transmitted rather than what goes through the attenuator.
I think that decodes from directly synthesised WSPR transmitters, as compared with audio modulated SSB transmitters, are easier.
Thanks for the contact Peter!