This master cylinder is made by TRW/Lucas. We can get the AP but it is more expensive. Both work just fine. Of course this is the cylinder for both brake and clutch. You can use regular brake fluid or silicone fluid. I use silicone because it does not affect the paint like regular brake fluid does. This is for disc brake cars. The bore [3/4"] is smaller for more pressure to the calipers.
Brake Master Cylinder - 1963 - 1966 - Spridget