Not all local channels display correctly without using a set top box. For instance WPCW Pittsburgh does not display as channel 19. The display instead is 63.1601. Some clear QAM local channels display correctly but many do not. Is is possible for Verizon to set all clear QAM local channels in Pittsburgh to display correctly when not using a set top box?
Be aware that only yhe HD versions of the channel will map to their "broadcast" channel numbers with the primary being x.1 (19.1 in your example assuming that it is an HD channel). All the SD channels can only be found by their QAM channel number (63.x in your example which is typically where SD channels are located in the Verizon channel mapping - HD is typically in the 70.x to 75.x QAM channel range).
There have also been issues with some geographical areas and specific TV sets not recognizing the mapping headers in the QAM signal.