This man has been puzzling me for a long time. I have several Ganges born, married and died in the Rochdale and Oldham areas at the same time that John suddenly appears in censuses claiming an Oldham place of birth. I haven't found any trace of a birth registration for him but often wonder whether I can claim him as one of my Lancashire Ganges. There was one other unrelated (to me) Gange family in Lancashire but they were a long way from Oldham.
His wife Mary Ann emigrated to Canada in October 1913. I had some contact with one of the Canadian descendants a few years ago but at the time they weren't interested in following up the family history.
John just remains an annoying oddity for me.