Since Robert and Rebecca Jane’s son Edward Robinson Johnston married in Glasgow in 1917, I looked for Edward in 1891 in Glasgow and found him age 17 with his remarried mother Rebecca Jane O’Grady, her husband, Patrick, and a stepbrother Michael O’Grady born in Scotland about 1884 since he was age 7. Edward had a brother James Harper Johnston, looks like age 21. So then I found the birth of James Harper Bowens Johnston in 1870 in Manorhamilton, parents Robert Johnston and Rebecca Robinson.
https://www.rootschat.com/links/01t54/https://www.rootschat.com/links/01t55/That means that Robert Johnston would’ve died before 1884.
Since Robert‘s first marriage was in Manorhamilton, I looked for his death there (after I checked Dublin) and I did find one of the right age using his age at his first marriage which was born abt 1838 and I did find one in 1880, age 42, but he was a hotel keeper. So is it him?
https://www.rootschat.com/links/01t56/But then I found Rebecca Jane’s remarriage in Glasgow in 1882 to Patrick O’Grady. She was age 30 (impossible since son Edward was born 1873 in Manorhamilton and Rebecca was full age when she married Robert Johnston in 1866 meaning born before 1845 so Rebecca was at least 37 in 1882) from Manorhamilton, Co. Leitrim, and her parents were Robert Robinson, Hotel keeper, and Susan McClure, both deceased. Rebecca’s father was Robert Robinson as per her marriage to Robert Johnston although her father was a farmer in 1866.
So I think I did find the correct death of Robert Johnston in 1880 and the correct remarriage of Rebecca Jane in 1882.