Crankcase machining ???

[frequentflyer]

It would fit on a bridgeport with a riser and could be machined at home, for the most part. I would be tempted to find someone to do the line boring for you as alignment is more critical, the rest is fairly straight forward. A drawing would be required or you could measure from an old crank case. I would also heat soak the casting to stress relieve once roughed as depending on what material and how it was cooled it is likely to move a bit when you remove material.
Having spent a little time in consultancy dont charge your time at the normal rate or it will end up a very expensive project.....