I repeat the first verse ("I must be going, no longer staying" etc) of The Grey Cock (Penguin book version). I also cut one of the verses. I think it works, needless to say, otherwise I wouldn't do it.

I also repeat the first verse of 'The Mermaid' ("One night as I lay on my bed" etc) and cut several verses from it – I don't bother with the whole retinue of crew-members stepping up ("then up stepeped the..."). The repetition of the first verse reinforces a suggestion that the whole thing is a possibly dream. Possibly, though not definitively.