I know a lot of these, if not all, are fold downs from the stock stereo mix. But since they were meant for AM radio, were they mixed hot like stock '60s mono 45s? If so, they might be highly desirable items, despite them not being dedicated mono mixes.
I never pass a title up that interests me. "Hot" mix on a case by case basis. I'm sure I have several 100, next listening session I'll pay more attention.
I've noticed some that are 'cut' a bit louder - like Stevie Wonder's 70's hits (including the mono fold down sides).