Ah, yes, the Retreat. I knew it was a Bonaparte tune, but here in Darkest Norfolk I don't have my usual resources to hand. Swarbrick used it, incidentally, as an instrumental break in Fairport's 'Sloth' (Full House). Who was it who introduced a quote from 'The Streets of Cairo' into it? I think that has been discussed here somewhere, and I used to play it that way myself.