Add to that fact it isn't even a real WW2 German marking. That seller is known for marking stuff with fake markings. He sold a cvx45 dated sling a few years ago- note that using capital letters CVX 44 you can't tell they aren't lower case - cvx CVX. FAKE.
Check the rivet heads on the buckle, aren't these ground flush on the pin that connects to the sling as well? I checked all of my slings and there wasn't one that looked like this except the repros I keep on my shooters...