"Thanks for your PM with the information."I don't see a need to PM anyone unless it's a secret?
That record of birth was available for you to download from SP to find the info. as to if/when/where they were married.
There are many people on RC with knowledge of different records who may have been willing to help on the open forum.
"they were married on 15th June 1873 in Preston. This was confirmed on Catherines birth certificate.
She was born on 11th May 1874 in *****hills ? Annan, Dumfriesshire and I think her fathers occupation reads 'power loom weaver'"Preston, Berwickshire or Preston, Lancashire?
There's no record of a marriage in Scotland on the indexes...
However, there are records of Irregular Marriages which can be accessed via different archives/libraries etc. although possibly at a cost depending on who holds the record...
https://www.nrscotland.gov.uk/files//research/irregular-border-and-scottish-runaway-marriages.pdfPossibly Leadhills?
"This would tie in as in the 1861 census Arthur Kavanagh is 13 a cotton weaver living with his family in Blackburn."Blackburn, Lancashire or Blackburn, West Lothian, Scotland?
"We are not allowed to post full images
Some of them are rather feint and hard to read"You can 'Report an issue' (top right side of image) being difficult to decipher & request a better scan on SP site, they're very helpful & quick to respond.
Annie