Sorry people, it's not a Brunch or a Toffee Crumble.
My sis has come up with this little teaser and she now seems to think it was made of an ice cream base on a stick, then a layer of chewy toffee, covered with those chopped nuts.
It must have been a Walls product, as there is nothing on that Lyons Maid website, and that goes back to 1925.