If you researched the "Lemon Law Wars" of the 90's, and the legal issues people and companys had during that time, being sued by Chrysler, you would have a different opinion. I had a magazine subscription then from "Mopar Performance", and they were sued just because they used the name MOPAR. He eventually changed the name to "MorPerformance", but was still too close to the word MOPAR. He eventually changed it to "Performance for the Chrysler Car Enthusiast". I think he eventually shut down the magazine. There was one issue that he had to recall, because he refused to comply, faced $10k/month or day IIRC and jail time if he did not recover all of the issues that were sent out. (I still have mine and the notice).
If you made it for yourself, they probably wouldn't care, but you are selling them, so I would just be careful. I could care less what you do, but just because you think you are a little fish, doesn't mean that you cannot get caught in the net... Just ask the kids/people that downloaded songs from Napster...