Complex sentence: He stayed with the firm after selling it to Sir John Ellerman in 1916, after problems with the third generation Wilsons losing interest, and had a troubled relationship with Ellerman receiving letters from him daily until his death from liver disease in 1926.
Split into simpler sentences: He stayed with the firm after selling it to Sir John Ellerman in 1916, after problems with the third generation Wilsons losing interest. Sanderson had a troubled relationship with Ellerman, receiving letters from him daily until his death from liver disease in 1926.