When my mum used to buy them for my dad from m&s when I was a kid they used to have a walnut inside them on the bottom as well as on outside on top , they were bigger n thicker chocolate too , like most stuff these days they are just cheap copies .
Quite right. The Guardian, ironically, ran a story on the change and its all down to Brexit. http://www.theguardian.com/business/2017/aug/16/downward-spiral-walnut-whip-brexit-twitter-nestle
I saw James Last in Tesco once. I believe you can still get them in Islington. They're filled with frothed organic Venezuelan tofu