Citations from both the Brooklyn Eagle and American Architect & Building News support the attribution. Note the typo in the AABN listing, which incorrectly places the row on the northwest corner of the intersection, on land occupied by the All Saints Episcopal Church:
Brooklyn Eagle, August 27, 1887, p. 1 ("Falling Off")
"Building Intelligence; Apartment-Houses; Brooklyn, N. Y.," AABN vol. 22, no. 610 (Sept. 3, 1887): p. xi.– "Seventh Ave., n w cor. [sic - s w cor.] Seventh St., 5 four-st’y brown-stone flats, cor. with store, tin roofs; cost, each, $10,000; owners and buiders, Cozzens & Brown, 377 Fulton St.; architect, I. D. Reynolds."
The corner building features a wonderful, circular corner bay window overlooking the intersection. This bay might have once been surmounted by a conical tower, a part of which still appears below the cornice. Many of the mixed-use buildings in 7th Avenue appear in historic photographs with such tower-like corner embellishments:
The corner bay is just visible at the far right-hand side in an old photo of the row across the street in the Brooklyn Public Library's collection.
Little is known about the firm of Cozzens and Brown, according to the Prospect Heights Historic District's Designation Report, where the firm is listed along with its Prospect Heights attributions:
We know a bit more about the architect, Isaac D. Reynolds, who established his Brooklyn practice in the 1860s and who designed many buildings in both the Prospect Heights and Park Slope Historic Districts: