I have to say that I think McNally's turn in SPLIT SECOND comes the closest of his noir heavy roles to matching his work in JOHNNY BELINDA and WINCHESTER '73. It's has more self-loathing than most, and the paranoia builds nicely. He and Alexis Smith are really fun to watch even when you've seen it several times and already know what's coming.
I have to think that someone at Republic created some interference WRT the screenplay for MAKE HASTE TO LIVE. Warren Duff had his hand in some terrific films in his career (beginning with HEAT LIGHTNING in 1934, including noteworthy Cagney films in the late 30s and THE FALLEN SPARROW, arguably John Garfield's first truly great performance and a nicely-turned MALTESE FALCON goes espionage) and his work more contemporaneous to this film had been very, very good (APPOINTMENT WITH DANGER in '51 and THE TURNING POINT in '52). Something really went haywire at this point, because Duff had only one more feature film credit after MAKE HASTE TO LIVE before his career trickled out into TV.