Demolition time at 491 Fifth

Permit finally posted for demolition of 491 Fifth , the first location of Tacos Nuevo Mexico, before they decamped next door. This little one storey building is next to the former OTB.  Every time I go by this corner I think about the passage in David S. Reynold's Walt Whitman's America, where we learn that in 1859 Walt's brother Jeff "lived (with his wife) for a time on Fifth Avenue near Twelfth in Brooklyn".  This little pearl of information is infinitely tantalizing.  Only 489 and 491 seem old enough to have conceivably been standing in the late 1850's.  Could Jeff have lived right there?  Could Walt have walked down my very block? Clearly I need to go to the Municipal Building & dig around.  Anyway, the demolition guys at 491 said that the replacement would be a three storey commercial buidling, in some form or other. Ho hum.