Vollrath generally has the size centered with a line under it with the handle pointed to 6 o'clock. I have a #3 Vollrath as well as a #5, and that is how they are marked on the bottom. The size is marked on the top of the handle as well. Otherwise, they are almost identical to your #3, with the rib where the handle meets the body of the skillet, and the oversized rim. Even with the photo magnified to 250X, I did not see any such markings. In my limited experience, I have not heard of nor seen an unmarked Vollrath, but I am sure the more knowledgeable members can provide better information. My #5 "WAGNER" SYDNEY O is almost identical, with a slightly smaller rib, but no oversized rim. (All three have a heat ring.) Either way, it sure is purty.