Complex sentence: Isherwood was a valued member of Lloyd's Technical Committee; he was also a Freeman and a Liveryman of the Worshipful Company of Shipwrights, having joined in April 1917.
Split into simpler sentences: Isherwood was a valued member of Lloyd's Technical Committee. He was also a Freeman and a Liveryman of the Worshipful Company of Shipwrights, having joined in April 1917.