Thanks to all who have tried with this one, but I have decided to pass this time. Google gives two references to "Etah". One is a town in India which I can in no way relate to cameras, but a more promising one is to a town in North Greenland, which was the starting point for various Polar expeditions in the 1890 to 1913 period. Rasmussen, Peary, Amundsen and Shackleton all started from there, and I guess it would have featured widely in the world's press at the time, which was also the period to which I would date this camera.
I know of cameras, also with no maker's label, called after events in the South African campaigns, which were common currency at the time, but which are largely forgotten by most of us today.
With the ephemerality of humanity being what it is, it is quite conceivable that whoever named the ETAH camera felt there was no need to add further details, because "everybody" knew about Etah town, and the then famous expeditions associated with it, and "everybody" knew the firm who made the camera.
A fair few nineteenth century British camera makers seem to have assumed that their reputation was carved in stone for evermore, so labels were not needed. Houghtons often stuck with "H.Ltd", Spratts used a model name but no maker's label, etc.
One theory for what it's worth. Thanks to all.