Yep. I am fine with artists contacting me if they want their work credited or removed. I only did it because it seemed like a good idea to secure them somewhere.
This is a perfectly reasonable response. I would even say in a readme “hey, I don’t know where all this came from originally, contact me if it’s you” or something along those lines. It’s fine though. These bitmap fonts are awesome even if a little light on char support. What would be really cool is an xml or json file with the rect positions of the chars in the charmap.