Erfurt Artillery Rebarreled by Factory?

[Edward Tinker]

please take a look at the FAQ - you'll find that Erfurt was using the notch - although later

In November, 1916, an amendment was
added to the P.08 Dimensional Tables that
allowed the receiver to be cut for the Artillery
rear sight.
Many Erfurt pistols dated 1916, 1917 and
1918 will be found with the receiver cut this
way. ("Imperial Lugers", Still, Pg. 61)
The discussion of the Erfurt proofed DWM
LP08 barrels came up on the old forum and
the consensus of opinion was that all LP08
barrels were made by Erfurt.

AND, yes there were 8 inch barrels rebarelled to 4 inch after the war - so it could be either - Erfurt only made artillery lugers in 1914 (and also 4 inch)