Yes, thank you Sinann, definitely a lot to Glasgow, Dundee is less obvious though. Simon may have lived in Edinburgh though before he went to New York in 1910, so that's on the east coast too I suppose. It would be great to be able to find him in some directories or any other definite markers. His grandson didn't know anything about him, so I wonder if Simon was living away in those last few years. He was a paver in the States, I guess a lot more work in cities than in Donegal.
I have just located him on the Scotland's people site and ordered his death certificate (not cheap though), so that will be good to see. Thank you for finding him in Scotland!