Here are some action shots - the tools make it easy but you can tune a reed without any special tools, just a file or engraver (even a razor blade can scrape off brass):
Are you sure you are removing material from the blow reed? When I first tried to tune a harp I had blow and draw confused until I played the harp without covers to see which reed was moving.
When I have had fractured reeds they seem to go out of tune very fast. Filing brings the pitch up for a few seconds of playing then it goes right back down. I can keep filing until the tip of the reed looks like foil but the pitch, while initially higher, goes right back flat. That sounds kind of like "I've been here 20 minutes and it won't budge."
