Just about all of the ML parts venders has the Tom Fuller Black English Flints & they are top notch in my book. Tracks, MBS, Log Cabin, Tip Curtis, Jim Chambers Flintlocks, The Possibles Shop, Cain's Ourdoors, October Country, etc. carry them.
As previously stated, Rich Pierce makes some white/gray flints & they work pretty good & are very reasonable.
:thumbsup: