I bought a little one ounce stainless-steel “drinking flask” on eBay a few weeks ago, it just arrived yesterday. It’s great! It comes on a key chain, which I use to attach the bottle to a belt loop. This means that the flask is easily at hand and it also means that I don’t have to worry about where to put the top. The seal is good. If it was perfect, the bottom would unscrew, but it doesn’t. At the moment, I’ve got Toque Quit in it. I don’t know how it would go with coarse, moist snuff. I’m not sure if the guidelines permit a link to a specific seller on eBay, so just do a search with words like “1oz” + flask + mini and so on. I’ve got two more coming. I wouldn’t be surprised if these are made by the same maker who produces the Toque stainless steel flask. If so, @Roderick has probably chosen wisely, with the flat, round shape, with no corners. But nice to have a bit of variety, and I’d feel bad carrying Dholakia White in a flask marked “Toque”, so it’s worth keeping in mind for those looking for alternatives. 

The image doesn’t really give much clue regarding the dimensions, does it? The diameter is about 3cm at the bottom, it’s about 4 or 5cm tall, the opening is about 0.8cm. It easily holds 10 grams of snuff, leaving space at the top so it doesn’t get clogged coming out.