A good essay, and one that demonstrates to me that some portion of the long "noir v. melodrama" discussion that has bounced off so many pinball cushions here over the years is seeping into your methodology. (Hope that's not too scary a thought!)

To give the "noir-o-meter" a plug (something I do with a lot less regularity than some...), lovers of Woolrich (and if one loves noir, how can one not have at least conditional love for ol' Corney?) will sometimes mistake his outlandish plots and colorful dialogue for "hard-boiled" when they are really anything but. And the noir-o-meter listings for key "hard-boiled v. melodrama" measures, as captured in this chart featuring nine Woolrich noirs, demonstrate this fact very succinctly:



THE CHASE, a more intensely developed version of the Woolrich formula (both by him and by Arthur Ripley, who definitely gave it something extra), is the anomaly here, but not too anomalous, as the score for "hard-boiled character strength"(far right column) indicate. (The higher the "Melo rate," the more of a "melo-noir" the film is; the lower the "HB character strength," the less hard-boiled the characters in the film are.) Overall "melo element strength" is at its strongest in NIGHT HAS A THOUSAND EYES...

...and NO MAN OF HER OWN is, as Dan asserts, a melo-noir all the way--and, I'd argue, would still be a melo-noir even if they'd decided to use the ending in the novel.