I've only read about these and here was one live and in the flesh! And she GAVE it to me!! She said I was more likely to make it up than she was, she couldn't remember how long it had been in her collection.
These were readily available in the 1960s and 70s, when Fair Isle sweaters were popular. I just Googled it and couldn't even find one on eBay. The wool is 'jumper weight' Shetland wool in a lovely heather green - and no moth holes!. The colorwork portion is done for you and buttons are included if you want to make the cardigan - and it comes with complete instructions. I guess they figured the colorwork would put knitters off from trying to make one themselves. Some knitters - like me - think that would be the fun and interesting part.
I feel like I own a piece of textile history.