Did you find the 109xx number inside the frame in front of the cylinder, on the butt, or on the front of the grip frame?
The actual serial number will be located in one of the latter two places. If the gun has oversize stocks or grips, you may have to remove them to see it. If the gun was made before the early 1950s, the serial number will be repeated on the underside of the barrel and on the cylinder face, although the numbers in these places may be non-matching or missing due to long-ago repair work. Only the number on the butt or grip frame is definitive.
The number inside the yoke cut, the part of the frame in front of the cylinder, may be an assembly number used at the factory to keep parts coordinated. It became meaningless once the gun was shipped. These numbers are often 4 or 5 digits, leading me to suspect that the number you posted may be an assembly number.