It is pertinent of former user to bring up the rifles, as they do affect the issue at hand. Those Zanzibari figures aren't carrying percussion muskets, their rifles were British-issued Snider-Enfields, (basically Enfield muskets converted into modern single-shot breech-loaders). The Egyptian army used the Remington, which does look rather different, again reducing these figures' utility as proxies for Egyptian regulars.
However, the far-flung Sudanese garrisons of the Egyptian empire cared little for regulation and tended to differ from the norm back in Egypt. Sam Baker issued Sniders and also 'shotguns' (smoothbore muskets loaded with buckshot) to his Egyptian army troops as he thought these better guns for bush-fighting. So again,the figures are pretty usable as ragged, filibustering Sudanese in the wilds of southern Sudan and Uganda, not so useful if you want them for other duties.