Calories and sodium in turkey stock -- a conundrum

I have a bunch of turkey necks, parsley stems, peppercorns, and bay leaves simmering away in the oven becoming turkey stock. Who knows how many calories or sodium it will have? Arguably, no one. Looking online you find everything from 86 calories a cup to 17. The 86 is likely from the one listing in the USDA database for something similar, "06172, Soup, stock, chicken, home-prepared."

There's no way to know what went into the USDA's stock. Was it made from just bones or bones and meat? Cooked or raw? Did they skim off any fat? Were there vegetables involved? Is my homemade stock likely to have more or fewer calories per cup? How can I account for the fact that my batches are different, one from another? Does it really have as much as 343mg of sodium per cup if I didn't put any salt on the meat or in the stock? Why does the USDA have nothing at all for turkey stock or broth?

Using the numbers from the USDA site for "06172, Soup, stock, chicken, home-prepared" seems the easy way to go but now, as we are entering into soup season, those high calorie and sodium numbers will be hard to balance with my limits. I could arbitrarily use lower numbers but am I kidding myself?

Anyway, if anyone out there has a bomb calorimeter handy, I could send you a cup of turkey stock.