Arl Ord sometimes double stamped their mark causing it to look almost unreadable. I have one that is double stamped, like the stamp jumped as it was applief. Yours could be more the a double muddying the letters. Or someone could have attempted to "remove" the mark as some do or make it look more like a scratch or such. For a while I did not care for imports but now that I have 3 I figure at least we know they were overseas and not just guarding the officers latrine at Ft. Dix.