As texastimbers noted those 6 and 8 tooth blades are fiber cement blades. They work really well for ripping and resawing hard hardwood.
Digging deeper, it appears that Sears used various blade suppliers, while maintaining some consistency in terms of blade part numbers for any particular type of blade. So for any given blade part number with a prefix for the supplier, and a suffix to denote the specific part, separated by a dot (period) in between... the suppliers sometimes changed (meaning different prefix), while the part remained consistent in specification (meaning same suffix).
The different table saw supplier codes are already widely known... 103. for King Seeley, 113. for Emerson Electric (who acquired King Seeley), 315. for Ryobi (I think... but I don't have any saws that new).
However, the different supplier codes for saw ACCESSORIES do not seem to be as widely known. And the codes themselves overlap, where the same code can apply to two different suppliers. In trying to learn what purpose Sears intended a super low tooth count blade to be used in a table saw for in the decades prior to Hardie Board ever being invented (previous fibrous cement type materials also had asbestos incorporated in the fibers, and by the '70's, it was well known that asbestos materials shouldn't be cut... especially by consumers of a lawsuit wary Sears), there are two supplier codes that seem to cover many, if not most, of the saw blades sold in that era:
720. Vermont American (well known makers of blades, taps, dies, drills, and other tooling)
720. (again, duplicated) Burgess Vibrocrafters Inc. (BVI) (not so well known maker of small woodworking machines, band saws in particular)
900. Black and Decker
The foregoing information is derived from Vintage Machinery's data base of owner/user supplied historical data on woodworking machines. In this instance, I have to assume that supplier code "9" is synonymous with "900", as there is no "9" separately listed on the otherwise dauntingly comprehensive database.
So, when I search blade part number 720.32469, I don't find much, but when I change suppliers and search 9.32469, I find the same 12" diameter 5/8" arbor 12 tooth blade described in Sears saw Accessories catalog as a "General Purpose" blade.
As a check, I investigated the difference between a few other blades that I have by suffix number, comparing the two different supplier code prefixes (720 and 9) with the descriptions of the blade for every given suffix (the actual blade number). I found consistency in the descriptions in each case that I tried, where I had a blade to compare. (eg, 32555 is the same blade, whether 9.32555 or 720.32555, and 32499 is the same, whether 9.32499 or 720.32499).
This still doesn't definitively answer what exactly is meant by "General Purpose", which is about as broad of a description as can be formulated in the English language. But the point is, at least during the time period of 40 years ago, these minimally toothed blades were not considered "specialty" blades. As a newbie to working with tablesaws, I find that to be interesting, if not instructive.