Wartime English Sundae, anyone?

This is Mo with a knickerbocker glory. I ordered it because the old lady sitting beside us was eating a chocolate sundae and it looked amazing. I was told that knickerbocker glories were 'English wartime' sundaes, so I thought I would try it, thinking it sounded like it would be really sweet. What makes them ration desserts is the fact that it's mainly tinned fruit, strawberry preserve, rather than syrup, and whip cream. Our really kind elderly server told us about eating them as a little girl on the seaside and it made me hate it slightly less, but overall, I was jealous of the chocolate sundae.