Anuerin Glyndwr is an official Labour blog, created and operated by David Taylor, a researcher for Leighton Andrews AM. I don't know the provenance of A Leaky Chanter. Perhaps one of my Scottish readers could help out.
UPDATE: A reader, Pavlov, has left this comment on another thread.
We in Wales also had a Labour smear blog, called Natwatch, which smeared and lied about Plaid Cymru politicians, and stooped so low as to mock the Sunderland accent of a Plaid Cymru Assembly member because she happened to be English. This site was run by Assembly Labour with the connivance and approval of elected politicians. Meanwhile, emails on discussion sites were written allegedly from Plaid supporters containing racist and anti-English comments. Every one of them was traced back to Millbank, where Labour henchmen were sending them out falsely.
They also made homophobic and sexist comments about Plaid members - these too were found to come from Labour HQ. What we need is for the people behind it to be outed in the same way as McBride and Draper and co.