Should be a 1959 with the copper coin. I have one too. Cream glass on front and gray glass on back. Mine serial# is YB 626 and is 68" and 47#.
The bow was made in 62", 64", 66", 68" and 70".
I always thought this was one of the nicest looking bows bear made. Listed in the 1959 catalog as costing $69.50. I paid about $200 for mine and think they are worth $200 to $400 on online auctions.