http://www.petermullins.blogspot.co.uk/2008/07/inside-st-nicolas-great-coates.html). The shape of the east window, the nature of the hangings along the east wall and the details of the false chancel arch (none of which survive today) are things I haven’t seen before.
The picture must have been taken after the work authorised by the 1900 Faculty (because the present pews are in place) but before the work authorised by the 1925 Faculty (because the present wooden backing to the altar is not yet in place), and it is interesting that the lectern (in a new position but with the same decoration on it as in the earlier picture) has not yet been replaced by the present brass First World War memorial lectern.
I can now see that I was wrong to suggest that the present semi-circular step in front of the altar was part of the work undertaken in the 1920s. The metal altar rails in this picture clearly curve (it is easiest to see this on the left / north side), and, now that I look at this again, I see there are repair marks in the stone evident today to show where this altar rail was once fixed. I would now suggest that it is may have been part of the 1865 restoration; the pulpit and the artificial chancel arch may well date from 1865 as well.
It is the chancel arch, of course, which is most striking. As far as I can see from the small amount of this arch which shows up in the earlier photograph, it appears to have been painted since the earlier photograph was taken.