1925 A.B. L.M. Ericsson & Co. Telephone

This is my circa 1925 A.B. L.M. Ericsson & Co. rotary dial telephone. It's the only telephone I own, other than a hand crank wall phone that you can't use with the current phone systems. I use this telephone for everything from calling the hardware store, to answering calls, everyone can hear me very clearly they say. I bought this telephone some time back; when I bought it, it was setting in a crate full of worn out, black 1930s and 1940s telephones, and it was obvious that none of those phones had been used for many decades. When I pulled it from the pile, it was covered in thick brown dust, every thing was about to rattle apart, the parts that should move were stuck, it was a mess. I cleaned it and oiled it up (you never think about oiling anything on a newer phone!, ha!), and now it works great. I have seen countless reproduction "French style" telephones which, to the untrained eye look nearly identical to this; the decals are different, the receivers are not Bakelite, like on the old ones or on this one, they have a volume control or say, "Made in Japan". I am a rather novice fellow in these old time phones, can anyone confirm that this is in fact a true 1920s or 30s telephone, and not a 1960s Japanese or Swedish reproduction? If anyone can tell me more about it, and when it was built, that would be greatly appreciated. Thank You!