It could be construed that an inland Sauer Taubenflinte Modell Nr. XXIX could be the same platform as the Sauer V,L & D Modell Nr. 300 or 280 by just having the same dimensions. After thumbin' thru some info the Sauer of which you are a custodian just might be a V,L & D Modell Nr. 300 having a doll's head extension & Krupp 3 Ringe Spezial Stahl w/ upper & lower scears. The V,L & D Modell Nr. 280, w/ Sauer Nr. 22250 being that & possibly in the same lot, would be a V,L & D Modell Nr. 300 but wears common Krupp steel tubes and had a straight rib extension. Images appear to show both the V,L & D Modell Nr. 280 & 300 had upper & lower scears. Need to find a V,L & D from the period and measure the frame. Sure, there were several others retailers trying to fill the void of the supply lines being cut during WWI & others who were beginning to absorb the faltering S,D & G. Even unbadged, I'd still hazard a guess your Sauer was in the lot w/ Sauer Nr. 22251 as the preponderance of evidence sure does tilt the scales that way. Can you provide an overall tube length & weight? Typical was 26", 28", 30" or 32" and weight commenced @ 6 pounds and varied to 8 pounds.

Cheers,

Raimey
rse