Possible related to Jim's suggestion above, there are two entries in google books for Fair Flora:

Fair Flora, Or, the Unfortunate Lovers. To which is Added, The Rose-tree, and Cauld Kail in Aberdeen, 1810, no publisher given.

and

An Excellent Garland, Containing, Six Choice Songs:
1 Guardian Angels 2 Old Adam 3 The Milk-maid 4 Come Kiss, Says He 5 The Nymph's Reply. 6 Fair Flora, pub Swindells. No date on detail page, but index gives 1790.

There are no previews for either.

I think one of the versions of Flora's Departure/Farewell has something like to which is added Fair Flora's reply (though that may not mean anything as far as the text is concerned).

Simpson in BBBM has, under the tune Young Phaon, a note that an 18C issue of Flora's Departure starts with Fair Flora beautiful and gay ("to the tune Wheel of Fortune, for which I have found no music").

I think several of the Flora's Departure ballads I looked at specify tunes. I wonder if Alan could post the tune to see if it compares with any of them (or something someone recognises). I'd be happy to convert sheet music to abc if that's easier.

Mick