Hi there,
Apologies for the slight delay replying, but I have just returned from a weekend visiting the Shelbourne family....I will try to explain as simply as possible.
Firstly I am only related to them by marriage, as follows
My sister in law Jane Harper b.1955 is married to Paul Michael Shelbourne, b. 1955, they married in Oct. 1978 in Leeds. Paul's parents were Fred Shelbourne 1929-1995 and Edna Bray 1931-2011, they married in 1953. Paul's paternal grandparents were Wilfred Shelbourne 1892-1957 and Amelia Whitehead 1896-1965, who married in 1919. Wilfred was the older brother of William Herbert of 1896 fame, and they were two of the six children of John William Shelbourne and Mary Jane Pulford.
I hope this is easy to follow, I do have various bits of information on several generations going further back and also on the maternal side of the family if you need any.
Keep in touch if there id anything I can help with.
Brian