Help Identifying Vintage Free Pistol

[red9]

I collect free pistols and consider myself quite knowledgeable in the field. This one, however, has me stumped. It has an overall 1920’s look, but with some features that make it difficult to date. The barrel is marked “H Scherping Hanover,” with German proofs. The lever in front of the trigger guard releases the trigger group, and the one on the right side completes disassembly. Features that I consider more modern are the rebounding hammer and sights with square blade and notch and dial windage and elevation (I am assuming that the sights are original).
Any information on this maker or other thoughts is appreciated.

Bob

[David M]

Have a look here.
http://www.germanguns.com/upload/forum.php
http://classictargetpistols.com/