J&B Golden Jubilee
Hello David - There is very little information regarding this brand, but our contact at Diageo was able to find out that Golden Jubilee was released to celebrate 50 years of the Paddington Corporation distributing J&B in the USA. The corporation was set up in 1936 and began to distrubute J&B in 1937, however, they're not 100% sure of an exact release date for this particular product. Also, the number 50 refers to the number of whiskies in the blend rather than years of maturation.
As for value, if you're in the US, contact Park Avenue Liquors (212-685-2442) or the Brandy Library (212-226-5545) - both do valuations. If you're in Europe, try McTears.com or Bonhams.com Let us know what you find out so we can post here for all to see.