Hi Stu.
Now look what you've gone and done. You re-opened this can of worms. LOL!!
Seriously, it's a great question that will probably be discussed around collector camp fires for more years to come. And yes, it's probably worthy of it's own Thread.
The answer(s) could be "all of the above". These flasks seem to fall in three "general" catagories. 1. Genuine antique items, say pre-1920's that were made of enough quality to be functional, yet could also be sold to a tourist. 2. Items made in the last three quarters of the 20th Century to be sold primarily to tourists. 3. Then there's everything else made from the late 20th Century through today. Many of the metal flasks I see for sale today look as if they were made from wax castings of an original. And they are even reasonably well made and functional, but just not old, or carried by a warrior.
Here are some pics of a well made - but still a Tourist item. Have no idea how old it is, but I'm guessing it's about mid 1950's or so. There are two reasons I know this is a tourist item. 1. The strap is made of tight woven, but thin cotton. Which produces more vivid colors, but not as strong as wool. 2. The most important feature is that if you poke a pencil dowm the spout, it is not drilled through to the base of the flask body. So there's no way to add powder.
Rick.