Ved,
As I was going through your build, I came across the problem with angle drilling for your steam ports and having to tilt the mill to do the drilling. I highly suggest getting an angle cube. I use mine a lot and don't have to tilt the Bridgeport head and re-tram it every time. Those angle cubes are pretty accurate to a hundredth of a degree. I use the angle cube with a tiltable vise that I have.
Grasshopper
As I was going through your build, I came across the problem with angle drilling for your steam ports and having to tilt the mill to do the drilling. I highly suggest getting an angle cube. I use mine a lot and don't have to tilt the Bridgeport head and re-tram it every time. Those angle cubes are pretty accurate to a hundredth of a degree. I use the angle cube with a tiltable vise that I have.
Grasshopper