This one is still niggling at me. Since I first posted this question I've found another reference, here in Victoria, Aus, to the "Chip Chop Cherry" variant of "Oranges and Lemons". Another woman who sang and played it as a child. The slight difference is that the choices for the "captured" child were between a golden apple and a silver pear - which raises the question about a link between this song and other references, in folklore, to magic fruit.
Anyone out there have any ideas?
Cheers, Joy