You havent admitted where your earlier knowledge is coming from ? Focusing on Lurgan, Shankill civil parish Co armagh Lurgan, which also appears to be used as a district ie a greater lurgan ie neighbouring parishes possibly
1833 The Belshaws in Lurgan, Shankill civil parish in Tithes Applotment Books
http://www.irishgenealogyhub.com/armagh/tithe-applotments/shankill-parish.php#.VlYRDUvBEYU included
Belshaw, Mrs. Townland: Lurgan Town Year: 1833
Belshaw, John Townland: Tabberhewney Year: 1833
Belshaw, Mary Townland: Tabberhewney Year: 1833
Belshaw, William Townland: Clanrolla Year: 1833
Belshaw, Wm. Townland: Tanaghmore North Year: 1833
in Newtownhamilton and other Co Armagh parishes heres one example
Belshaw, James - Townland: Tullyvallon Hamilton Year: 1830
1846 from
https://www.emeraldancestors.com Francis XXXXX marries Sarah BELSHAW Lurgan Armagh
1854 from
https://www.emeraldancestors.com William Belshaw marries Jane XXXXXX Lurgan Armagh
1857 from
https://www.emeraldancestors.com Benjamin Belshaw marries Anne e XXXXXX Lurgan Armagh
1864 Griffiths valuation see
http://www.askaboutireland.ie/griffith-valuationBelshaw John Tullyvallan Newtownhamilton Armagh
Belshaw Jane Tullyvallan Newtownhamilton Armagh
Belshaw Samuel Cavanacaw Lisnadill Armagh
1881 from
https://www.emeraldancestors.com Andrew James XXXXX marries Margaret Belshaw Lurgan Armagh
1900 from
https://www.emeraldancestors.com James Kernaghan Belshaw marries Lizzie XXX Lurgan Armagh
1901 Irish census for Co ArmaghI note one or two onto the 1911 results
1911 Irish census for Co Armagh the homesteads consisted
29 in Avenue Road (Lurgan Urban, Armagh)
Belshaw William 49 Male Head of Family Church of Ireland Co Down Damask Weaver Read and write - Single [But in 1901 he didn’t exist in Co Armagh, I think he came from Newtownards]
1 in Carrickaness (Glenaul, Armagh)
9 in Edenaveys (Killeen, Armagh)
72 in Tullyvallan (Newtownhamilton, Armagh)
107 in Tullyvallan (Newtownhamilton, Armagh
24.1 in Abbey Street (Armagh North Urban, Armagh)
other websites
http://www.belfastforum.co.uk/ has 9 Belshaw entries in their search engine
one of which has ‘Otto ‘replying with two facts one of which is
Civil Marriage 6th July 1881 Andrew James Burnett to Margret Belshaw at Lurgan Civil Registrars Office in the Parish of Shankill Lurgan County Armagh.
PRONI has wills
William Belshaw Grant : 9 February 1898 Administration of the estate of William Belshaw late of 75 Avenue-road Lurgan County Armagh Damask Weaver .. granted at Armagh to Robert Belshaw of 122 Melody-road Wandsworth Common London S.W. Inland Revenue Officer the Son.
William Belshaw Date of Grant : 16 August 1939
Belshaw William of Avenue Road Lurgan county Armagh damask weaver died 15 January 1939 Administration (limited) Belfast 16 August to Alexander Minnis bank manager. Effects £407 3s. 3d.
www.lurganancestry.com fohas some births and parents
Heather asks
www.lurganancestry.comJAMES BELSHAW, JONATHAN BLACK, HUGH HALL COCHRAN, and MATTHEW WELLS.
They were all Watch and Clockmakers in MAIN STREET, Lurgan in 1840.
‘Colin’ appears to have a family tree containing several Belshaws in Co Armaghin the 1860s his interest is in Mary Jane and Lucinda in Castleblaney Co Armagh
http://www.GenesReunited.co.uk/