Roger, pull the lock free and scrub the inside (the vent hole blows residue out/partially down into the works)
If the flint sparks sparks, go ahead and try w/ it.
https://www.youtube.com/watch?v=8Rb0s3YAGOA
If problems, they are available from these guys:
https://www.trackofthewolf.com/List/Item.aspx/141/1