Again going by style I've always thought Morren's pieces mostly somewhat earlier than 1800, say about 1780.

I'm not sure how this fits in with your posting at the moment but Peter Buchan was briefly apprenticed to Randall before setting up his own press in Peterhead. Unfortunately very little of what Peter actually printed seems to be extant. For someone who had such an enormous collection of ballads published it has always remained a mystery that he didn't appear to print any of them on his own broadsides, or maybe he did and they somehow disappeared.

Is the Buchan version from Gleanings p46? That's the only Buchan reference I have to a version. Most if not all of the 'Gleanings' pieces were straight off broadsides. The BL version I have seen but not got a copy of was printed in Aberdeen in 1775 as the Gosford Tragedy and this had 17 and a half double stanzas.