The old Bristile exhibition There was a glassed-in rotunda in the paddock, Along with a witch’s castle, and other delights, Toy soldiers marched on an endless belt, Families picnicked. One of those sights   The guide-books never mentioned, yet unique In its own hardly-noticed way, With a sort of innocence, a small essence Of childhood wonder on a sunny day.   Who bought them, dressed the ranks, installed The machinery that kept them on the move? Someone long forgotten, bent To create this strange little act of love.   Slouch-hatted diggers, Britain’s Royal Marines All in perfect step, rifles…