Raimey

a possible reason for the second date with the proofhouse is obtaining the Nitro stamp. I have a similar thing on one of my rifles: first BP proof in Vienna 1896, nitro reproof in 1943 (easily understood because the 1943 marks are so different).

The Nitro proof and the 1909 date might eliminate some of the cartridges in my line-up.

The Vienna proofhouse is still active - maybe they have the old ledgers still?
http://www.bmwfw.gv.at/TechnikUndVermessung/beschussaemter/Seiten/BeschussamtWien.aspx

fuhrmann