Craigster, you are indeed correct; but the OO Grade was not cataloged until 1901, so the O Grade was the lowest grade gun offered in the serial number range noted above. SAC serial numbers had reached 5 digits long before 1901; and, with a few recorded exceptions, SAC guns seem to have been manufactured in numerial sequence beginning at SN #1 and progressing upwards into at least the 39,000 serial number range (I haven't recorded numbers above 40,000 at the moment, nor an OO Grade below serial number 20000 at this point). As FYI, an even lower grade SAC double gun was added to product line production in mid-1904, a hammergun; but these guns were given a unique serial number beginning an "H" prefix. This model was also sequentially serial numbered beginning with the number 1.
