In Germany, which has been in business since 1919. I contacted them with photos of the buttons and they confirmed that those buttons are their models from the WWII era. They're leather covered, black, and they look sharp against the lingering greenish gray of the exterior leather of the coat.
These buttons are also a larger size than usual, at 21 mm. Most German greatcoat buttons from WWII are 19 mm.
The lining is original and in fine shape. Altogether this coat is a real looker.
The chest size is 36 U. So it's an average smaller size among German WWII greatcoats, not one of the rare huge sizes. If you like the coat, feel free to make an offer. And if you have any questions, I'm happy to answer them for you. The measurements for this coat are as follows.
Armpit to armpit: 20 (51 cm). Shoulder to shoulder: 18 (46 cm). Drop length from the base of the collar to the hem: 45 (114 cm). Arm length from shoulder seam to end of cuff: 25 (63.5 cm).
The item "Original German WW2 leather overcoat, nice condition" is in sale since Wednesday, December 28, 2016. This item is in the category "Collectibles\Militaria\WW II (1939-45)\Original Period Items\Germany\Uniforms". The seller is "siegfriedblitzkrieg" and is located in Buffalo, New York. This item can be shipped worldwide.