I have recently purchased a Colt Python, polished stainless, 4" barrel, the serial number is PNO6331.
Can anyone tell about this number, never have seen the PNO prefix before, Colt says the manufacter date is 1995.
Any help will be appreciated.

You don't trust Colt?

The publicly available Colt serial numbers stop with 1985.  After that, ONLY Colt can tell you when it was made.

The last published serial numbers for the Python were in the "T" range.

I suspect the number isn't PNO (letter O) it's probably PN0 (NUMBER zero).
So the prefix would be PN and the numbers are 06331.  That's the standard Colt followed from the 1970's on.  This would allow running the series up to PN 99999.

Only in God and Country.   Not that I don't trust Colt, but they are not very free with any information.  Because I have never seen the PN prefix (which doesn't mean much) I was just wondering if it had and special significance (Presentation Nonce or Police Novelty).
Anyway, thanks for the information.  I appreciate it.

I have a PN 10XXX, was told a 1996 build by the owner.  I never verified with Colt though