The tolerance on electrolytics was typically -20%, +80%. So a 10uF electrolytic could be anything up to 18uF, hence 16 should be fine.
You should be able to get 10uF, though, it's a common value. Are Mojo just out of stock?
As a more general point, components aren't made in the 1-2-5 sequence any more. The preferred values for electrolytics are 10, 22, 47, 100, 220, etc.
33 and 68 are also available but not quite so common. 16 is unusual.