Now that I'm looking at this on a monitor and not my phone, it's clearly, and expertly, rusticated rather than sandblasted.
I love this pipe because of all of the anomalies. A French made pipe commemorating an enemy German war ace, with an English "Algerian Briar" stamp from a time when Algerian briar was considered 2nd rate material, so people didn't go out of their way to stamp "Algerian briar" on a pipe. And the rustication, which expertly mimics a sandblast, from a time when both were uncommon.
The only other time I've seen rustication carving like this was on. mid 20's a Barling Elite, which is featured on the Pipedia Barling page. The pipe feels like a '20's pipe. So, what's the 1917 about? Just so many anomalies, it's wonderful!