I don't know what happened with the post about British musket flints, But as someone who shoots antique and blackpowder firearms, I can say that British musket flints are considered the best.
During the American Revolutionary War, The patriots, ( that's us Yanks) were handicapped by the fact that there isn't any flint in the U.S. Wrong geology. We have chert, which is similar and agate which will also strike a spark, but those materials are not as good as flint.
When you are fighting with flintlock firearms, you need good gun flints. The Redcoats had the best British flints. The materials used by the Americans would frequently shatter after one shot!
British gun flints are still imported into the U.S. for use by antique firearms enthusiasts and a musket flint costs the equivalent of 2.75 Euros.