Serial numbered grips

Cold numbered grips prior to WWII because the guns were final polished with the grips on the frame to insure a perfect fit.

This stopped after the war as standard practice, but some guns during some post-war periods were numbered. This seems to have stopped sometime in the 1960's.

When Colt did number the grips, they wrote the numbers inside, usually with a pencil.
Later grips with numbers that are hand written or stamped into the wood or marked with an ink stamp are not serial numbers, and appear to have been stock or inventory numbers.

So if your Cobra grips have numbers inside, they may not be a serial number, and they will probably be hand written with a pencil.

My 1960 Cobra did come with its original grips.SN written in grease pencil

I don't have much experience with the double action revolvers, but Single Action Army grips were almost always numbered to the gun. When wood grips were used they were marked with pencil (or later, grease pencil), but with the black plastic grips, the numbers were marked using a sharp steel or diamond tipped scribe. Even some Peacemaker .22 and New Frontier revolver grips were marked with the gun's serial number in the early 1970's.

- - -Buckspen

This practice seems to mirror what S&W did as well. This also explains why sometimes grips from a similar gun do not fit another gun, dued to the final fitting and polishing process. Grips are individually tailored to a specific gun during assembly processes in the factory.

Many Pre-War revolvers have stamped numbers on the backside of their stocks.

Among other models Pythons did not have serialized grips.

My 1966 Python with box, target and other papers has numbered stocks.Tom

My 70's Lawman snubby has the s/n ( matching the revolver ) written on the inside of the stocks in what looks like silver Sharpie...