There was a series of 22 in 1955, a series of 20 in 1959 (of which the blue fox is one), and a series of 20 in 1960. There are many variations in 1955 and there are a great many different colors in all years out there with some pretty rare colors. There is also a very short produced coin in 1960 (Bud Daley) with catalog values starting out over 200$ in good. Either of the big catalogs would have checklists, and I suspect Beckett would have a list also.