thank you for the replies ..
there are some discrepancies in my evidence:
his name is Henry Miller in all but 1 document, a child's birth cert, when he appears as John Henry Miller (incidentally his first son's name and we know his father was John so could well have been John Henry too, maybe that is why he used Henry)
we have a rough birth year of about 1848 (possibly Carlisle), no death year but we do know that he is alive in 1884 when his youngest child is born in india (this is where he is down as John Henry Miller) and the next evidence we have is the 1891 census when his wife Rebecca and all the children appear back in Carlisle and she is a widow, so we have a window of 1884-1891 for his death. I was hoping his service record would shed some light.
we have lots of details of all his kid's births, exact dates and places (1 in carlisle 1871, 1 in dublin 1872 and 5 in india 1875, 76, 79, 81 & 84)
he is down as a private in the 40th regiment of foot but appears on his son Robert's marriage cert as "deceased, sgt. in the 40th regiment of foot, bandsman"
he then appears on his daughter Annie (my gt grandmother)'s marriage cert as "sgt in the border regiment"
so as you see on one hand we have a lot of info but on the other we have confusing discrepancies
an interesting point is that that there appears to be a prominent Henry Miller of the 40th regiment of foot at the end of the 1700/beginning of 1800's, obviously not him but does bring in the possibility of them being related, maybe a family tradition in that regiment? .. strange though, if it is true, that none of my gt gt grandfather's sons followed on .. they worked on the railway.. bad experience in india? maybe railway work was more attractive at that time?
i have had a search for him on findmypast as suggested with no luck, apart from a Henry Miller who died in Aden in 1890 (i think) .. the regiment is reported to have been there after india and around that time, so it could be him .. no more details for him though
any help would be very much appreciated
Ronan