Martin if is a Model XIV it is an upgraded variant with 3 Ringe Krupp steel tubes, ejectors and upper rung engraving, unless added later. Also I don't recall seeing a standard Model XIV with the set screw on the floor plate. I don't mean to call your hand on it but you or your father designated No. 133 as a Model XVII, http://www.altejagdwaffen.de/Catalog.33.0.html?&L=1 , & I think Doverham's engraving to be the same or a notch above Krause #133. That is unless you have the page of the Sauer ledger with both serial numbers.

Kind Regards,

Raimey
rse