Sorry, but this is definitely a repro. There were many firms which manufactured the genuine WW1 U-Boat badge, from the originals issues in 1918 through the 20s and 30s and into the Nazi era ( as replacements) but none ever had this style of fittings, which are typical of modern fittings used on fakes ( and on the "1957" denazifgied style awards).
Thanks for the info. Much appreciated.
Here are some original examples for comparison.
A period example with needle pin made by Walter Schott
A "between the wars" example with wide pin by Meybauer
A Third Reich period replacement piece in Zinc, which has lost its gilding.
I understand that the issued pieces were hollow-stamped, and that the solid badges could be private purchased well into the 1930s...I was wondering if a Screwback-Variant has been known to exist?
Not correct I'm afraid. The first original badges were designed and made by Walter Schott of Berlin and were most definitely solid.
Private purchase pieces during the 30s were certainly hollow stamped. The Steinhauer & Lück catalogue from the period has them and specifically states they are hollow (see attached).
A screwback version of the WW2 U-Boat Badge was made by Juncker but so far this is the only Screwback U-Boat Badge that has surfaced.
Does this mean that all the solids are wartime issue, and the hollow ones are postwar? I thought the stamped hollow versions were the scarce ones...
Bear in mind that the U-Boat Badge was only instituted in 1918 so was only created a matter of months before the war ended. By then, Germany was in a chaotic state and I doubt that many crew members actually got their badges. Finding a photograph taken before the end of the war, with the U-Boat Badge being worn, is very very difficult.
By the end-stages of WW1, many recipients of even some high awards, were simply receiving confirmation of their awards with an award document and left to their own devices as far as obtaining an example was concerned.
Schott was the original contractor so I doubt that many additional firms would have been involved in their production before the war ended. A Schott piece is the only type that I, personally, would accept as possibly being a wartime issue example but even here, Schott was certainly also producing them well into the postwar period so its impossible to tell whether a Schott badge was produced in 1918 or in for example 1920, after the war.
The vast majority of original Imperial U-Boat Badges are from the inter-wars period.
I have certainly never seen or heard of a hollow stamped piece actually proven to be from pre-November 1918. In my opinion they are all private purchase pieces from the 20s/30s/40s. Indeed Steinhauer were still making hollow Imperial U-Boat Badges until recently, from the original tooling. They are easy to find and generally fetch much, much lower prices than the original solid pieces.