Oswin Musgrave - Parents

I realize the fact that it's uncertain whether his father was James or John Musgrave but having having conflicting parents attached makes tracing complicated. I don't know if I'm related to him or not. I am if his father was John Musgrave but maybe not if his father was James. .

And are the two mothers both names Isabel Musgrave the same person?

Thanks for any clarification on Oswin's connections.