That's a good plan. Also, over the decades, I've received a good number of letters like the OP's, claiming trademark infringement when there was none. Each tim

That's a good plan. Also, over the decades, I've received a good number of letters like the OP's, claiming trademark infringement when there was none. Each time, I just replied myself, explaining that my use was not infringing and that I won't comply with their demand. Saying, basically, "sue me". Not once have I heard a peep from them in response. In my mind, I figured that if I got a real pushback, then I'd have a lawyer deal with it for me if it was worth fighting, or I'd just go ahead and cave if it wasn't. I never had to make that decision, though. The deal is that, unlike copyright, trademark is explicitly something that you can lose if you don't proactively defend it. As a result, companies will usually send out these sorts of letters for any use of a trademark, legitimate or not, on an automatic basis, but won't take it any further unless they really think there was infringement. Sending out a letter is basically free and doing so covers them on the "have to actively defend the trademark" front.