A brief rant about turkey liver

So, if you are dealing with a turkey and want to make giblet gravy or turkey stock, every recipe you will find tells you not to add the turkey liver until very late in the process, as it will make the product of your labors taste bitter. BUT! Does ANYONE tell you how to recognize which of the three (in the case of my recent turkey) small items in the paper bag IS the turkey liver? They do not. I performed a Google(TM) search* for images of turkey liver and was sadly disappointed. One site from Dorling-Kindersley had a lovely photo of various kinds of turkey "offal" (the wonderful old term for such things) but at least on the website, they were not identified. Other sites had photos so murky and taken from so far away as to be quite useless.
Now, I know what a human liver looks like (more or less, shapewise), or a beef liver. One might assume that a turkey liver looks similarly shaped but smaller, but of my three items, one looked like a heart (2 chambers) and the other two both looked as if they COULD be livers. So, this time, I used chicken broth for moistening the stuffing, etc. and put the turkey neck and giblets into a bag in the freezer. But tomorrow I plan to make turkey soup with the carcass and it will be Use It or Lose It time for the innards. Can anyone help?
*A friend of Cordeliaknits works in the legal department at said search place and she says this is the proper terminology. She also says the amenities are all they're cracked up to be.