Thanks, I'd heard of Scotland's People, but never used it, I've used the LDS site, Ancestry, and GenesReunited a fair bit over the years.
Thanks for the tip though, as it's already given me a possible match - the 1911 census contains a match at 54 Oran St, Maryhill for a Michael Hayes, 43, born in England, and a Mary Hayes, 41, with 9 children, 5 of which match the names I have;
James 16
Daniel 14
Louisa 12
Frederick 11 - Freddy
Richard 10 - Dick
Honora 8 - Nora
Gilbert 6 - Gilbert
Margaret 4
Leslie 2 - Leslie
Also, I searched on LDS of Honora (instead of Nora), and found immigration records fro her arriving in New York in 1925 (https://familysearch.org/pal:/MM9.1.1/KX96-LPW), so I think this looks like a very likely match.
Thanks for your help!
Scott