From McGuinn and Bazelon's book:
William H. Jones, Waterbury, CT, 1835-40. Former partner of the Robinsons. Left Massachusetts in late 1834 and began making buttons in Waterbury c.1835-37. I think your buttons are civilian fashion ones and all date to the same second quarter of the 19th century (1820-40). I just found a two piece here in southwest Georgia last week with the same backmark.