Hi I too have traced myself back to this Richard Ramsay. Did you have any luck finding out any more about him?
I have linked to William Fenton on ancestry who seems to think he served with the Gordon Highlanders. This would link the Dalhousie name, which is very Scottish, but I haven't found any other info. i too am Scottish and hope to go to Edinburgh this summer to do more research.
Let me know if you have any other info and who are you descended from?