Yes, these are the two sizes of "No. 1" shells. However, I truly suspect that the blue Pearline, and especially the Primrose Pearline, are about as rare as it gets in regards to colors made in the shell patterns. When I bought the Primrose Pearline 2 years ago at the Glass Faire, I showed it to several very knowledgeable dealers and all of them suggested it was an American-made piece. I even showed it to Raymond Slack, and he did not recognize it. His partner said she thought it was Davidson, but was not certain. If a room with 110 "cream of the crop" dealers from the heart of England don't recognize it as Davidson, I guess I would question your remark of "all the shells Davidson made these seem to be the most common." The shells might be common, but the colors are not. I suspected that blue pearline was made, but until I actually saw these for sale, I had no proof that they existed, and I consider myself fairly knowledgable on Davidson's glass that was made in blue or primrose pearline.