"He took a particular Marxist approach to the Victorian collectors."
Not particularly:
As far as I know, Marxists never had an approach to Sharp (I've read enough Marx to come under that description - not strictly true)
Dave [Harker]'s hatchet job was all his own.

Dave Harker was SWP, and no friend of the CPGB or the likes of Lloyd and Maccoll. In the final sentence of 'Fakesong' he states: "How far he [i.e. Harker himself] succeeded in doing so, and whether the effort was worth it, will be best judged by his comrades in the Gorton Branch of the SWP and those in other socialist parties."

I had an interesting chat recently with one of Mr Harker's former SWP colleagues in Manchester, who had been horrified by his assault on folk song and found his methods lacking in proper Trotskyite analysis, so it would appear that, even by its author's preferred criteria, 'Fakesong' wasn't an unbridled success.

Having spent some time examining Dave Harker's work, it's clear to me that, while he is well-researched in terms of having examined much relevant source material, his representation of it is biassed and tendentious. Following some of his footnotes back to their sources often reveals that they are misquoted or presented in an inaccurate context, and he quotes very selectively in order to present his targets in the worst possible light. Compare for example his account of Baring-Gould's relationship with source singers with that provided recently by Martin Graebe in his excellent biography, which gives a far more detailed and sympathetic analysis of the reverend's motives.