Original  1939 German Nazi Party Iron Eagle Clasp with pin.
I bought it  in Poland in 2012 along with some other collectable items. I showed it to some experts at the National gunshow , they all said it's original . 
 
History of German Iron Eagle Clasps : 
In 1939 the German Nazi party introduced the Clasp to the Iron Cross (Spange zum Eisernen Kreuz).  a holder of the 1914 Iron Cross could be awarded a second or higher grade of the 1939 Iron Cross. To permit the two medals to be worn together, a "1939 Clasp" (Spange) would be worn on the original 1914 Iron Cross. ( See one of the Image Clasp with the Iron Cross  )  It depicted a national eagle clutching an oak leaf wreath surrounding a swas above a trapezoid bearing the year 1939. The clasp was attached to the 1914 Iron Cross medal ribbon. The ribbon was then worn through a tunic button of the uniform.
 
The Clasp to the Iron Cross (Spange zum Eisernen Kreuz) was a white metal medal clasp displayed on the uniforms of German Wehrmacht personnel who had been awarded the Iron Cross in World War I, and who again qualified for the decoration in World War II
During the war, over 100,000 clasps were awarded
A holder of the 1914 Iron Cross could qualify for the same grade of the 1939 Iron Cross. To permit the two awards to be worn together, a "1939 Clasp" (Spange) was established to be worn with the original 1914 Iron Cross.[1] It depicted a national eagle clutching an oak leaf wreath surrounding a swastika above a trapezoid bearing the year 1939.
For the Second Class, the clasp was attached to the ribbon of the 1914 Iron Cross, either on a ribbon bar, or when the ribbon was worn through a tunic button hole. For the First Class, a larger but otherwise identical clasp was pinned directly on the upper breast pocket above the Iron Cross 1st class (1914) of the wearer. This pin-back clasp was usually awarded in a presentation case.
While Nazi era awards were initially banned by the Federal Republic of Germany, in 1957 many World War II military decorations, including the Iron Cross, were re-authorised for wear by qualifying veterans. With display of the swastika banned, the clasp to the Iron Cross was re-designed as a silver rectangular bar bearing the date '1939', with a miniature Iron Cross in the centre of the bar.