Hi, I have two books on Bybee pottery. In 1922-1929 Genuine Bybee was made in Lexington Ky. Their mark was Genuine Bybee and other simuliar marks. In the early 1930ties the Cornelison Pottery in Bybee Ky. accquired the rights to use the Bybee mark. Their mark was the word Bybee inside the shape of the state of Kentucky. They also used BB and just Bybee and later in 1970ties Bybee pottery and stickers. They are still in business and only sell directly from factory. Kovel’s have a blue glazed plate listed in 2012 book priced at $6.00 8-9 in. Some are on e-bay asking 12.95 and lower. A lot of their wares are unmarked.