(Below in italics is from the 2004 East Durham National Register listing; not verified for accuracy by this author.)
Duplex. 1-story hipped-roofbrick duplex with large metal casement windows and 2 front porches. One porch has metal porch posts, the other boxed wooden posts. Not listed in 1960 CD.
This appears to be an error on the part of the NR compiler. The house is actually 515 Maple, not 601; it appears to be pre-1960s in style - particularly the steel casement windows. A deed search shows that the lot was sold to CG and Helen Duffy in 1954; the house was likely built soon thereafter. Unfortunately, it is listed as a non-contributing structure to the NR district, although it should be contributing.