Scotland's People shows two births registered in 1919 in the name of Thomas Henry Pitman, one in St Rollox Glasgow, the other in Govan Glasgow.
When Thomas Pitman married Maisie Lynas in 1919, his address was given as 25 Craigmore Street. The 1918 Belfast street directory cites
"Pitman, Thos., labourer" for that address.
The Pitman family was living at 25 Craigmore Street in the 1901 census (confirmed by the 1901 Belfast street directory):
http://www.census.nationalarchives.ie/pages/1901/Antrim/Windsor_Ward/Craigmore_Street/975232/By 1911 they had moved to Charlotte Street (before presumably returning to Craigmore Street) - BTW, note Thomas senior's birthplace is given as Dorset England, the Pitman name was/is not common in Ireland:
http://www.census.nationalarchives.ie/pages/1911/Antrim/Windsor_Ward/Charlotte_Street/168409/The couple in question were Thomas Pitman (father George) and Margaret McMinn (father Henry) who got married on 16 January 1895 in St. Anne's Church of Ireland, Belfast. Both fathers were carpenters. The civil marriage for this couple and the civil birth records for the children are available on GRONI online, choosing the "Full" viewing option for any record shows an extract of the original document (5 credits, currently £2):
https://geni.nidirect.gov.uk/The Belfast City Council website has a number of Pitman burial records (including that for Percy in the 1911 census), given the rarity of the name, they may well be related:
https://ssl.belfastcity.gov.uk/burialsearch/burialSearch.aspx
