bsi022604: Process of elimination follows:
It isn't a .32 Rimfire, the Number 2 Old Army didn't go that high in the serial range.
It isn't a .32 Single Action, ditto as above.
It isn't a New Model Number Three, ditto as above.
It isn't a K32 Masterpiece, as it lacks the K serial number prefix.
It isn't a K32 Hand Ejector as their serial number range is higher than the number you quote.
It isn't a .32 Military & Police, they have a C or S prefix tot he serial number.
That leaves the following options:
It could be a .32 Double Action 4th Model, serial number range was 43406 to 282999, manufactured between 1883 & 1909. This was a top break five shot revolver with an external hammer, caliber was .32 S&W.
It could be a .32 Safety Hammerless Second Model, serial number range was 91418 to 170000, manufactured between 1902 & 1909. This was a top break five shot revolver with an internal hammer and a grip safety. Caliber was .32 S&W.
It could be a .32 Hand Ejector Model of 1903 - 5th Change. This was a six shot swing out cylinder revolver on the small I frame, similar in size to today's model 60. It came with a 4.25 inch or 3.25 inch barrel, caliber was .32 S&W Long. Manufactured between 1910 & 1917 in the serial number range 102501 to 263000 between 1910 and 1917, if this is your father-in-law's gun it probably dates to 1910.
It could be a 32-20 Hand Ejector Model of 1905 - 4th Change. This was a 6 shot swing out cylinder gun chambered for the .32-20 cartridge, using the square butt medium sized K-frame. Barrel marking should be .32 W.C.F CTG.
These were manufactured between 1915 & 1940 in the serial number range 65701 to 144684.
If it doesn't fit any of the above categories then a photo will be needed to identify it.