things that I have two or more identical ones of
You're looking for something fancier and more arcane than "duplicates" aren't you :(
Does a thing for making tomato puree really resemble a potato masher, or did you just mean similar in the sense of "hand-operated thing for making X". Do there exist potato-mashing machines?
I remember a litigant on courtroom TV saying that she was known for her cooking-- this had something or other to do with the case-- and when asked about the menu of the meal in question, one thing she listed was "home-made mashed potatoes". HUH? Why would someone who claims to be known for her cooking even need to specify "home-made"? It would be like someone bragging about their renown as a baker, and then announcing that they've made a cake from scratch.
tubes of condensed milk..
Does it keep forever? That would be a benefit. I think in Norway they put tomato paste in tubes, so you can use whatever amount you need instead of looking around for something to use up the remaining 2oz. of your opened can.
Hand coffee bean grinders.
I used to have one of those. Now I have an electric one but I've never used it for anything but grinding spices. Never buy anything pre-ground except ginger, which is qualitatively different from fresh root.
otoh I could never get the hang of a corkscrew. I have to use the kind with the two flat bits that fit around the cork. (I'm also inept at sharpening knives. Now that my father no longer lives within convenient knife-sharpening distance, I use a gadget someone gave me.)
And then there's the juicer that screws directly into the lemon, which cuts back on cleanup. Or it would if I could remember I own it.
:: wandering off to see if there's anything new