NY Times article circa 2000 about the Bowery, written by someone who spent a lot of time there as a child in the 60's probably.
"Today on the Bowery the tallest building -- other than the 1970's Confucius Plaza in Chatham Square -- is the 10-story Salvation Army Chinatown Corps, No. 225, near Rivington Street; most are three or four stories."
"Still seedy around the edges, the Bowery is not yet gentrified -- there's no Starbucks, no Gap -- and it's not clear whether it will soon look more like SoHo, to the west."
"Old-timers gape at a two-story terraced gray penthouse, recently erected atop a dark orange brick building." ---- (While there are other seemingly older penthouse structures visible, I think this one is the first real sign of the beginning of what the Bowery has become.)
Also, another mention of its unique street arrangement:
"The Bowery interrupts the city's straightforward grid. Streets like Prince, Spring and Bleecker on the west side, and Stanton, Rivington and First on the east, end -- or begin -- at the Bowery. In some cases, the names change: Delancey becomes Kenmare; Bond becomes East Second; Great Jones becomes East Third."