EK1 screwback L/56 opinions

[emilitaria_usmc]

A fellow collector mailed this to me yesterday.
I did a WAF search and it looks consistent to other L/56 EK1's except this one has a flat back.
Does it look original to you guys?

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1939 EK1 Screwback L/56: magnetic core, bright silver plated frame, full paint, flat back, 44 mm, 17.6 gm, 26.8 mm silver plated non magnetic disc, stamped L/56 (Funk & Brüninghaus, Lüdenscheid) on inside of screw plate.

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[emilitaria_usmc]

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L/56 ... Funk & Brüninghaus Lüdenscheid
14.3 gm, 3.3 gm

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[sanya13]

IMO this is a very nice original F&B screwback type
/for me yet always missing this the type (I looking for)/