Magazine Identification - Need Help, Please

[Luke]

Just received the Imperial magazine shown in the image below. The serial number is clearly 6843, and the suffix appears to be a lower case German "u" character.

In "Imperial Lugers" on page 15, Jan Still lists reported serial numbers for Imperial Lugers, and ONLY the 1917 DWM LP08 shows serial numbers in the "U" range.

Am I correct in reading the suffix as a German script "u" ?

Does anyone have later information on serial number ranges for Imperial Lugers?

Thanks for your help.

Luke