Hello Moira
You may be able to find your John Kerr if you contact the Rotherham Cemeteries direct. FreeBMD shows the death of John in September qtr 1874 Rotherham age 71. 9c, 372. So if you explain you are disabled and you cannot get to the office yourself to look at the books containing the burials etc, they may be more obliging to help your search. Their link is on the Rotherham Council website. The other thing is I am doubtful it would tell you where he was born.
Also Moira, do you have a copy of John's marriage certificate? If so what is his father's name? I know the census can be a real pain if you have ancestors born in Scotland and Ireland, as it does not always tell you where, exactly!! Both are very big places and trying to pinpoint a location can be hard sometimes. I have found this to be the case with two lines of Irish ancestors in my tree.
The Rotherham Archives hold a few books of transcriptions from a few cemeteries, may be again if you contacted them and explained your circumstances they might do a look up for you.
Either way I hope you find your answer, please get back to us and let us know how you are getting on. If you have any more queries please do not be afraid to ask.
Happy hunting and kind regards.
Joy