Can't think how I managed to miss this thread until now. Not that I have much to offer. But for what it's worth:

First the records: The Richardson Zonophones must have sold in their thousands. In the not-so-long-ago days when every junk shop had a pile of old 78s 'The Old Sow', 'Sarey', 'The Farmer's Boy' and 'Buttercup Joe' turned up regularly. I'm pleased to say I have all of them, but even in immaculate condition they are far too common to be of much resale value. The Richardson songs were, incidentally, regularly played on the wireless in the thirties by early disc jockeys like (were there any others?) Christopher Stone.

Harry Garratt I don't know of - and I really can't believe that 'Buttercup Joe' had anything to do with Garrick. To me this song has the flavour of earlyish music hall - say 1860s or 70s. Fred Albert (not, I think, Alberts) would certainly be a 'possible'. Michael Kilgarriff's great book (always the point of first reference for the Victorian and Edwardian music hall repertoire) lists well over thirty songs by this singer and remarks that he 'claimed to sing only his own songs'.

'Buttercup Joe' is not in the Kilgarriff list and it doesn't appear under that name in the BL catalogue, but until we know more, Fred Albert (1844-1886) seems as good a guess as any. Wouldn't be impossible, though, for Harry Clifton.

The grammatical transposition of 'her' and 'she' to represent country speech would have been happily embraced by a music hall lyricist of the time, but it is an adopted rather than invented form. You can still hear it in the West country, for example.