The Hydrovac brake booster is a reproduction of the Bendix booster that was licensed and manufactured by ATE as the T50 booster. This reproduction booster is available on eBay and the Boursin Auto company ( https://www.boursinauto.com/search/?Keyword=hydrovac) Choose the Buick 1956-1960 booster.

The kit contains the hardware and instructions to install this booster in a Mercedes-Benz 190SL.

Here is a link to: the Hydrovac Installation Instructions