Hi,

    I have photographs of over 70 different 1946 Chief engines, and not one has the number in the style of P.O. 3195.  Police machines, in general, did not have a different numbering system than civilian machines.  Export machines also used the same numbering system as U.S. stateside machines.  The NYPD stamped carburetor is seen on New York City Police bikes, and this is the one exception to the civilian numbering.  Carburetors are easily replaced, so its presence cannot be used as conclusive evidence for Police service.  If the machine is otherwise original, a siren hole in the rear fender is the best proof of former Police service.  If the engine has not been restamped, the P.O. 3195 stamping is likely a number supplied by the 'Motor Vehicle Authorities' for a machine that had lost its paperwork.  The left case half (at least) is likely a replacement supplied from the factory in unstamped condition.   To see what the original engine had for a number, the frame number can supply the serial number.  If the frame is 3462468, the engine would have been CDF2468.  The highest number 1946 Chief I know of CDF7081.  To know more, you would have to find the person that stamped the engine; and that is just about impossible.  Sincerely, Steven Bailey baiste@sgu.edu