The AMT 49 merc is very nice and would work just fine (I don't know if they really were used as police cars tho) I think MPC made a snapper 49 merc that came as a police car in at least one issue....I've never seen one in person tho.
The AMT 49 coupe came out about 50 years ago and has been re-issued many times..and is currently available. The revell coupe is heavily chopped (the roof) and can't be built stock and thier woody is stock except for the engine. Both are readily avaliable too. (Tower Hobbies has all 3 currently with free shipping too btw) And ALL 3 are very nice kits.
The Modelhaus makes a 59 chevy sedan delivery..that uses Revellogram 59 Chevy for parts..not really a "kit" tho. The only 60 sedan delivery I know of is the old "custom" from Monogram and it is the only "kit" of a 59-60.
I'm curious why revell decided to use a 30-31 style firewall in the 29.....that bothers me far more than the port spacing on the engine. Anyone know what kits had the stamped valve covers for this engine?