Hi Mike & Will.
Firstly Mike, I found your man in my 1860 East India Register as Bombay Artillery 2 Battery, so he must have ordered (purchased) his sword whilst he was still BHA; I wonder what he did with himself during the Mutiny, he was certainly in service during the mutiny period.
I have a sword that belonged to a chap in the Bombay Artillery, he joined right on the turn from EIC Artillery to Royal Artillery, and although his name is not printed in the 1860 list, it was written in by hand by another officer who was also in the Bombay Army, and he was original owner the 1860 list that; my chap also served with the Royal Horse Artllery in Abyssinia 1867-68 and Afghanistan 1878-80.
Will, the scabbard you illustrate is an experimental version produced for the 1899 pattern sword, they were made in two different types, one with steel mounts and one with non-ferrous mounts and I'm not sure if they were ever general issue.
The problem of steel scabbards blunting swords was a problem that was dealt with in Indian from a very early date, and noting in the pre Mutiny years circa 1848, John Jacob of the Scinde Irregular Horse solved the problem for himself by using nickel silver for the scabbard construction, with a "full" wooden lining, the wood extending right up flush with the top of the mouth.
Apart from metal scabbards, wooden leather covered scabbard were also used to some extent by officers in Indian; these would probably have had steel shoe and sling ring mounts, or alternately carried in a frog with no other metal mounts other than the shoe and drag, but not always with the drag.