That looks like a Bendix booster that would be used on disc brake cars. It appears to have the original drum brake master cylinder attached (Disc brake master cylinders have the lines attaching from the inboard side of body).
Here is a pic of an original booster on a power drum 1968 Charger 383 4V. It is the flat type which is crimped together.

4963430-DCP_1117.JPG (98 downloads)