I second the calls to Egyptian forces but there is, in my view, another gap in 1/72nd colonials that Strelets would now be well placed to plug.
Also a good match to the late colonial Slade Wallace-equipped Brits would be Pathans for the North West Frontier campaigns of the 1890s. The HaT Indian infantry and Bengal Lancers plus the Strelets British and Highland infantry go a long way to representing one side of the conflict.
It is unlikely I will ever buy into the NW Frontier as a gaming period. This is because I already have extensive collections of two other Colonial wars: the Zulu Wars & The Sudan.
The space & time needed for a third period would make a further committent foolish.
However, I'm not posting to rain on your parade. I am but one potential buyer amongst hundreds who would be keen. I think the NW Frontier would be an excellent area for Strelets to enter with a plethora of great sets. I believe it would get a lot of interest & generate sales.
And who knows? If the figures are tempting enough I may show I am indeed foolish & buy into it.