In addition to medical activities and correspondence with Louis Pasteur, he was considered an expert on campanology and local antiquarian matters, and he served as a Justice of the Peace for Norfolk from 1886 to 1895.
Henry R. T. Brandreth contends that Seccombe, originally an Anglican layman, had become an Orthodox Christian in the early 1860s in London.
He may have been consecrated to the episcopate in 1867 by Jules Ferrette, "Bishop of Iona" in the Ancient British Church.
Brandreth identifies Seccombe as "the principal mover in inaugurating the Order of Corporate Reunion, or at least in laying down the line in which it was to follow."
Seccombe assumed the name and title "Lawrence, Bishop of Caerleon" after supposed consecration as a bishop in 1877 in Italy, and worked with Lee and Mossman to reordain clergy of the Church of England with a view to establishing a body with unquestionably valid holy orders that could be received into the Roman Catholic Church.