I do not remember where or when I found this, but I have used it on occasion.
http://vintagemachinery.org/Craftsman/manufacturers.aspx?sort=1
Craftsman OEM List
One frequently asked question concerning Sears tools is "Who made this product for Sears?" Often the model number will have the form nnn.xxxxx, in which the 3 or 4 digit prefix indicates the OEM (Original Equipment Manufacturer). Some prefixes have been used for more than one manufacturer, and several manufacturers have been assigned more than one prefix.
A list of manufacturers is compiled here. Those entries in UPPER CASE are from a Sears document, "Standard Brand Source Number Reference", dated May 1995. Those entries that contain lower case are for tools that have been compared to non-Craftsman models made by the same manufacturer, or from indications as to the OEM in the documentation or model number tag. Lower case entries also contain data extracted from internet sources, USENET articles from the "rec.woodworking" newsgroup, participants of
www.owwm.com, or emails from knowledgeable enthusiasts. (Thanks go to Ken Vaughn for compiling the original list.)
Since it is difficult to verify the accuracy of these sources, any new data is simply added to the list. Please note that this list likely contains errors and is certainly not complete. If a prefix is not included in this list, I do not know the OEM (and it would be a waste of time to email me--sorry). However, if you have additions or corrections, please contact Brian Kachadurian.
001 Stevens
002 Lemont Industries
071 Agri-Fab Corp
093 Ametek
101 Atlas Press (now Clausing Industrial)
102 Walker Turner
102 Robert Shaw
103 King Seeley
103 Roper
103 Sarlo Power Mower Inc
106 Campbell Hausfeld
106 Tate Mfg Co
106 WHIRLPOOL
107 Millers Falls (Dunlap electric drills 25830 & 1345, drill stand 25630, and hand planes)
108 Covel Mfg Co (now Clausing Industrial)
109 AA Engineering / Double A Products
110 Charglow
110 KITCHENAID
110 Syncro Devices / Syncro Corp
110 WHIRLPOOL
111 Watson Mfg Co (4 jaw lathe chuck)
112 Parks Tool Co
113 EMERSON ELECTRIC
114 Pioneer Gen-E-Motor
114 ROYAL
115 Rixon