On the 'salads', I've found that the store-made salad in the Superstore Deli (an example) is made with a Miracle-Whip type dressing instead of mayonnaise. Bad news. Furthermore, you will have to go back sometime and get the ingredient list and nutrition info if you can because everybody's recipe is different! More Bad news. If you haven't gone out of ketosis, maybe it's not an issue. I find, in an emergency deli situation, the safest thing to do is buy 6-8 ounces (~300-450g) of roast chicken or turkey breast, and get a fork and a mustard packet.

As for the marinated smelts, I come from a Dutch background myself and am familiar with the marinated fish problem and have actually seen containers/cans of the fried and marinated smelts or other small fish (sardines) in the store. Nutrition info can probably be had from those containers, although I'd be careful and check for sugar in the marinade, that's very usual (a sweet and sour approach).

As for the carbs in the flour, the only thing that might change the carb count would be setting the stuff on fire, pretty well but on the bright side, it ought to be fairly low if you don't eat more than 1!

Hope this helps some.