NEW YORK — Gristedes has covered up the word "Trader" on the exterior signs of its revamped store on 14th Street here after rival Trader Joe's filed a lawsuit alleging trade dress infringement. The 10,000-square-foot “Trader John's” store, shown here before changing its sign, opened as simply “John's” last week just a few blocks from Manhattan's only Trader Joe's location. In an interview with SN, John Catsimatidis, chairman of Gristedes parent Red Apple Group, said he was considering alternative names, but saw the store as a test concept for possible conversion of other Gristedes locations in the city. “This is an experiment,” he said, noting that the new store would stock primarily private-label items. In filings with the U.S. District Court here last week, Monrovia, Calif.-based Trader Joe's said it withdrew its initial objection to Gristedes' internal decor package, but argued forcefully that the word “Trader” should not appear in the store's name.