Paul, yes I have a No5 that has seen service in India. It has a couple of peculiarities, for starters it has been blued to a fairly high quality finish. Besides the transverse screw, the only other hint to India is the tiny, almost microscopic RFI stamped on the top of the elevation dial- other than that it is unmarked. The receiver had been buffed/ polished but not quite enough to remove the original " No5Mk1 ROF (F) 11/44". The serial # is on the r/side of the butt socket, but that's about all the markings on the rifle. The bolt knob is drilled 7/16".
I've had this discussion somewhere before and remember being told the reason behind the bolt knob variations being for both a machining datum and set up differences in the different manufacturers processes. (it may have been Peter telling me then).