Colt's "New Pocket Model" was introduced at serial No. 1 in 1893, and production ended in 1905 at some number within the 30,000 serial number range. At that time they revised it, added some new safety features, and renamed it the "Pocket Positive." The first one started somewhere in the serial No. 30,000 series and continued until 1940 when the model was discontinued at around serial No. 159,000, although a handful were made thereafter - one as late as 1960. A revolver in the 131,xxx range should have been made in 1928, not 10 years later.
The only difference of consequence between a Police Positive and Pocket Positive is the size and shape of the butt. The Pocket Positive's is smaller and more rounded then that of the Police Positive. They do use the same cylinders, but it is unlikey they'd interchange fithout fitting. Also, I think it's unlikely that your gun would be chambered to use the .32 Long Colt at so late a date. A "New Pocket Model" would be another matter. Yes, there is a little loosness between the cartridge and cylinder wall, and should be. The serrated/matted topstraps were introduced around serial No. 150,000 so your revolver shouldn't have this feature.
Given that others are apparently having problems with certain lots of Federal ammunition, I think that this is likely the cause of your problem with split cases, not the revolver itself. At this point I would do nothing to the gun, except perhaps clean it.