Here's one you may never get a chance to see. Base embossed with "PATd" (using a small, large-case "D", underlined). On the dome is a fancy script outlined "2" in a circle. Pinhole has a Pennycuick type dimple. Base is oddly flat, slightly canted inward. Profile is similar to some crown embossed 102, but the skirt is more concave, or "flared".