Guys thank you all so so much for your input. I'm trying to read each comment, take notes and refer to my own.
To address the connection between Robert and "his father" David.
Robert is buried with Ellen and some children in Banagher Parish Church. I have researched the church records and could not find any Robinson born into that church in the preceding years. The first record of a Robinson at the church was the marriage between Robert and Ellen in 1881.
So I began looking at other local churches, the next being Cumber Upper and here I stumbled into a treasure trove of Robinson's. The church records go back to 1811 so I was able to research from there and have written down every Robinson birth and parents. *Note of caution here the church records at this time only detail the date of baptism and NOT the date of birth. Robert was born in 1848 and the first mention of any Robert being born was a baptismal record for May 6th 1849 the parents being a David and Jane, farmers from Binn. As with most records they are tricky to read but I subsequently found 8 further baptismal records for children of David & Jane...I may have missed one or two
