Alright so I'm taking a quick stab at this.. there are only 2 Edward Roach/Roches in Nova Scotia in 1871 that match your age range on the Census. Possible he may be dead by this time. Neither are in Cape Breton sadly. Here is the link to the Census pages at Library Archives Canada http://www.bac-lac.gc.ca/eng/census/Pages/census.aspx
Worth noting that I checked 1861 and found only the exact same 2 gentlemen, in 1851 I see the guy in Pictou was there, but the one in Halifax doesn't seem to be around.
There is an Edward Roach (62) in New Glasgow, Pictou with wife Margaret (62) and son G. Robert (22) (http://data2.collectionscanada.ca/1871/jpg/4396280_00088.jpg)
And an Edward Roche (65) in Ferguson's Cove, Halifax with wife Elizabeth (58) and children; Thomas (23), Bridget (14), Richard (12).
When I jumped up to 1881 the guy in Halifax is still alive, but I would guess our friend in New Glasgow died in his 70s.