Q - what do you mean - "if the winkle was used as a food item"? It is. Not "if". It is.   You can buy them from stalls in East London (I can point you to at least one) where they are consumed with some degree of relish, although not by me. Too gritty by far for my delicate palate. Whether or not any dictionary has a derivation for it earlier than 1925. And yes, the word is also a euphemism.

And wankle isn't used in British English as a verb, even if it's a type of engine - at least, if it is, I've never heard it. Which doesn't mean, of course, that in some obscure corner of the UK someone isn't using it at this very moment, but I think it's a typo for or misreading of wangle.

I quite like the endearments in this part of south east Wales, where you are likely to be addressed as "flower", "petal" or "blossom" as well as "love".