I remember reading in Victorian novels as a kid about calf's foot jelly being taken to invalids and wondering what the heck it was. Asked my mom, who told me it was like Jello made from meat (with the ensuing revelation that Jello was made from animal bones, etc.). It rather lost its allure after that.
Something else I've seen mention of repeatedly in mid-20th C and earlier culinary writing and really want to try is oysters on the half shell with hot chipolata sausages, which, if the sources are to be believed, was a common way of serving them. Not so in any of the many restaurants I've been in. I could of course whip it up for myself, but my wish is to see it on a menu and be able to indulge finally and luxuiriously in it.
Any other literary or other references to intriguing and unattainable dishes in your experience?