ZF4 Scope Identification

Received a German ZF4 scope as part of a deal last weekend but after reading up about all the fakes out there, I have no clue whether its real or a fake. I will say if it is fake then it is very well faked. The story was that the seller bought it from a ww2 vet who brought it back and somehow attached it to an M1 Carbine, which the seller bought and replaced the scope. Of course thats word-of-mouth but i dont have any reason to believe that he was trying to pull a fast one on me as the price was very reasonable. The scope markings say "Gw ZF 4, dow, 24192". The glass is intact and clear. The scope rings i dont believe are original and were used to mount to the M1. The scope came with what id say is its original lens cover. It is very old looking and feeling with no markings i can see. I was wondering if yall could give me your opinion on its authenticity and if it is fake/real what it might be worth and maybe even if you could narrow down to when it was made. Ive attached a bunch of pics but can add more specific ones if needed. Sorry for all the picture parts, i was having trouble with the picture size. Thanks yall!!!

Part 1 http://imgur.com/gallery/nCAN47T
Part 2 http://imgur.com/gallery/N0YDUUB
Part 3 http://imgur.com/gallery/QKAp7EC
Part 4 http://imgur.com/gallery/8tOjBxY
Part 5 http://imgur.com/gallery/8ZDnT6W
Part 6 http://imgur.com/gallery/2WLwtOt