The Diocese of Worcester has issued a redesigned website which includes a Parish Finder powered by Google Maps. The only issue is that the only diocesan parish that offers the Tridentine Mass, St. Paul's in Warren, is not mapped. (For your information, Mass is at 10:30 am every Sunday.) Only diocesan parishes are mapped, no schools or religious houses.
According to the map there are 19 parishes left within the city limits of Worcester and none of them offer the Mass of All Time.