Form 406 was used for various designs, thus The Beer Stein Library does not list an estimated value. They were probably special orders for customers, and the value will depend on localized interest. PuG (Print under Glaze) 1/2 L steins are typically in the $150 to $200 range in mint condition in a stein auction. About 30% of that price would go to the auction house. Sales on the Internet, such as ebay, would be at the lower end or less. You might have more success offering it in the California marketplace.