I picked up this shard yesterday while hunting an 1870s era line. It has a smooth base, single skirt, and is threaded. Note the H.G. markings, so I think it is a Hemingray product. Photo two is an attempt at a profile shot. I cannot determine the CD for this piece. It is definitely not a CD 133. The skirt almost looks like a CD 151, but there is no inner skirt, and the outer skirt is too short anyway. Any thoughts? Help would be appreciated.