These are the real deal. Bail and wire mid-century mason jars. I use them for storing rice, sugar, dry beans, corn meal. They look better than the store packaging, you can see through them and have the quick on/off lid using the old school bail and wire.
You can look up on various websites the age of these jars - they vary but right around the 50's and 60's - the cursive of the writing is what gives it away.
I do not to provide a strong cautionary tale for these however. If you plan on storing both sugar and salt in them, keep them separated or marked. I made the mistake of putting two big teaspoons of salt in to my morning coffee one day. And surprisingly it tasted absolutely horrible. Don't be me.