I am 100% certain that I have the right family but there is obviously something weird regarding Catherine's maiden name.
You have it as Jones (on John's death certificate and also on his marriage). Family I found show, on childrens births, her name as Murtha. Checked on a daughter with a less familiar Christian name i.e. Sophia. She married a Patrick Smith 12/11/1895 Govan and states her father Thomas as 'Iron Ship Plater' and mother as Catherine Murdoch!
Knowing that Thomas still alive 1895 then looked for his death - he died 22/2/1902 (alas, in Govan Poorhouse). Shown as 'Ship Plater', widower of Catherine Murdoch. Informant is YOUR John McEwan of 95a Langlands Road, Govan. Checked 1901 census and your John and family are living at 95 Langlands Road!
So, this proves the family on 1881 census - when Thomas shown as Dock Labourer - is the correct one. They had 6 children - John b.10/9/1860, Mary b.26/12/1863, Catherine b.23/3/1866, Sophia b.21/3/1872 and an Annie bc.1875/6.
I only have access to transcripts of Scottish census and past experience shows that all kind of weird transcriptions come up. In 1871 (on ancestry) family name has been transcribed as 'Kevlin' so heaven knows what original looks like! (Thomas a 'Labourer at Iron Works'. In 1861 (on ancestry again) family name transcribed as McGloan! This time Thomas is 'Boat Yard Labourer' and it's just him, Catherine and baby John aged 6 months i.e. b.1860.
So, 1861 John is 6 months b.1860 (correct), 1871 bc.1861, 1881 bc.1862, 1891 bc.1862, 1901 bc.1859!
I see, sadly, that Catherine McEwan died 14/2/1902, just 8 days before Thomas. This reveals where the name Jones comes from - she is shown as married to Thomas McEwan, Iron Ship Plater, and her parents are shown as Thomas Murdoch, farm labourer (deceased) and Catherine, nee JONES!
Even weirder - the marriage details on Sophia's birth certificate show that Thomas McEwan (or McEwen - most early records have this spelling) and Catherine Murtha married 18/1/1859 Castle Eden, (which is in Co. Durham), England. Castle Eden came under the registration district of Easington but cannot find marriage entry in English records. Should be registered Mar.qtr.1859 Easington - nearest I can find is a Catherine Murtagh (??) but no corresponding Thomas McEwan/McEwen.
So now it's a marriage in England to find!!
Annette