You may already have seen when searching British newspapers that there is a marriage for his second son John Frederick Muntz (30th Regiment) formerly of Baddesley Clinton Warwickshire, in Freeman's Journal and Daily Commercial Advertiser (Dublin, Ireland), Wednesday, March 12, 1879. Marriage was on March 8th at St James Church, Piccadilly, London, to Alice Maud EYRE.
So you may find him in Warwickshire records?

Sue