For sale is a NOS power brake booster installation pkg for many GM models from 1964-66. Even if you only need a couple items it's a steal. The part number for this cylinder is 9784874. It is impossible to get this NOS plating correct.
I don't have the original box but clearly it's all NOS. This is perfect for survivor or restoration. The item "1964 1965 1966 GTO CHEVELLE 442 PONTIAC CATALINA NOS BRAKE BOOSTER TRI POWER NEW" is in sale since Sunday, December 22, 2019. This item is in the category "eBay Motors\Parts & Accessories\Vintage Car & Truck Parts\Brakes".
The seller is "ravjudge" and is located in Le Mars, Iowa. This item can be shipped to United States.