Unless and until you have been legally served with a cease and desist as required by the laws of your state it is just a legal bluff. It doesn't hurt them to make the phone call and ask if you comply they save time and money not needing to get an attorney involved.
However fair use does cover you using the trademarks to legally sell the equipment you already own. If they don't like it, give them the option to purchase the gear at your advertized price. That will cost them less than going through the legal motions.
However fair use does cover you using the trademarks to legally sell the equipment you already own. If they don't like it, give them the option to purchase the gear at your advertized price. That will cost them less than going through the legal motions.