When I was young, my father liked to read mysteries. His favorite writers were Mickey Spillane, John D. MacDonald and Ross Macdonald (Kenneth Millar). I probably read "A Deadly Shade of Gold" half-a-dozen times. Those books formed my concepts of what a fictional detective is like and how he or she should act. To this day, I can't stand wimpy PIs and the English cozies leave me cold.
Millar and MacDonald died in the 1980s. Spillane died in 2006.
The one thing I didn't care for were the last few Spillane "Mike Hammer" novels. Max Allan Collins collaborated/finished up three of Spillane's manuscripts (so far). I read them over the weekend. The only clinker of the three was the "Goliath Bone". The book is set in the last decade.
Collins or Spillane rewrote the back story for Hammer, because they had to, I guess. If you read the `40s-`50s books, you know that Hammer and Pat Chambers, Hammer's friend, were cops together on the NYPD. Hammer was a NYPD sergeant who went into the military after Pearl Harbor. Chambers stayed in the NYPD and rose to be a captain of homicide detectives.
The problem is, though, that in the "Goliath Bone", Chambers is still on the job, which would make him probably the only 90 year old cop in the NYPD. Collins changed Hammer's back story so that he went into the Army underage, then spent two years on the NYPD after he got out before he became a private investigator. That change maybe took a decade off Hammer's age, but he would still be either pushing 80 or past it, when he is running around Manhattan, getting into fights with bad guys. And the change in the back story leaves hanging the question of how a rookie beat cop would then become buds with a homicide captain. (Not to mention that the ending truly sucks.)
The other two, "The Big Bang" and "Kiss Her Goodbye" were set in the 1960s and 1970s, respectively, and they work better. "The Big Bang" has two glaring anachronisms, but you can determine them for yourself.