Hello Elizabeth Like you I also have Stirling and Marshall ancestors in Cumbernauld. My main interest is the Marshalls. As you say they are very difficult to unravel, If it's any help to you here are some death details. 1) William Marshall, Farmer, died 23 June 1857 @ 11hrs am. aged 72. Address. North Muirhead. Son of William Marshall, farmer, deceased and Sara Allan deceased. Cause of death Paralysis 2 months. Buried Cumbernauld Churchyard. Reported by son Allan Marshall. 2) Isabella Marshall, maiden name Stirling, proprietor of Muirhead of Dullater, widow of William Marshall, died 29 May 1870 aged 75. Father Allan Stirling farmer, deceased, mother Isabella Steele deceased. Cause of death eysyselas? debility. Reported by Robert Marshall son. The 1851 Census. Muirhead William Marshall aged 72, Farmer of 26 acres b. Cumbernauld Isabella Marshall, wife, aged 54, b. Cadder. Children all born Cumbernauld = Allan 29, Stone Quarrier. Margaret 20, Charles 16. Isabella, visitor, aged 13 born Linlithgow. 1851 Census William Marshall aged 48 Hand Loom Weaver, b.Cumbernauld. Isabella, wife, aged 48, b.Cumbernauld. Children all born Cumbernauld James 21, Limestone Miner. Margaret 18, Handloom Weaver. Robert 13, Handloom Weaver. Mathew, 7, Scholar. Isobella 4. These, I think, are your two Williams and Isobella's. Hope this helps Best wishes Mary