Did he say where he got it?

Assuming (as I may as well, as a working hypothesis) that the Gaugers recorded an arrangement collated from the various texts and tunes in the Greig-Duncan Collection, then the couplet (one of two from a Mrs Clark, August 1906, whose set was the only one beginning "The bonnie ship, the Diamond ship") would run

Provisions we've got plenty, we've liquor up in store
Wi' our tarred dress we'll reach Strathness and we'll gar yon tavern roar.

Obviously some small changes have appeared, as you'd expect; and the Gaugers also tended to introduce broader dialectal forms than their sources had necessarily used. Of course, they may have got it somewhere else entirely; it's a pity they didn't say. Greig remarked in his MS notes that it was a pretty well known song, but that it was difficult to get complete copies of the words.